Apple’s iOS platform seemed to come out of nowhere and take the world by storm in 2007. The introduction of the first-generation iPhone set in motion a chain of events that lead up to the holiday quarter in 2011, when Apple recorded the most profitable quarter in technology history thanks mainly to unbelievable iPhone, iPod touch and iPad sales. No platform is selling as quickly as Apple’s mobile platform right now, but iOS is still in its infancy and the fact remains: as hot as iOS is right now, and as popular as smartphones and media tablets are, no platform installed base on the planet even comes close to approaching the size of Windows right now.

The Future

Microsoft said this past December that there are now more than 1.25 billion PCs running the Windows operating system. Billion, with a “B.” Smartphones are the hottest segment in consumer electronics right now and people are buying Apple’s iPad in droves, but even still, more people around the world rely on Windows than ever before. This is because the software that powers countless businesses from the ground up is built on Windows. From web browsers to accounting software to point-of-sale systems to 3D animation software to word processors to custom proprietary solutions and far, far beyond… Entire industries are built on Windows.

The future is anything but “post-PC.”

We are now entering the post-post-PC era, and its focus is the PC. A new, smarter, more versatile PC. A PC that lets users browse the web casually in bed and work with massive databases in SQL Server. A PC that can run a $0.99 news reader as well as it can run proprietary $99,000 CRM software. A PC that is as ideal for playing Angry Birds as it is for running a modeling environment that allows its user to build schematics for a skyscraper. This is the future of computing.

That is not to say Windows 8 is an “iPad killer” or that media tablets are going away. Far from it. While their functionality may overlap in a number of areas, light-duty tablets and full-fledged PCs serve different purposes and will continue to coexist for some time. What we will see, however, is media tablets becoming more capable and more powerful as PCs become better suited for touch input. At some point down the road the two categories may merge, but neither will “win” or “lose.”

The OS

I’ve spent the past week playing with and working on a Samsung tablet powered by Microsoft’s new operating system. It’s nice to be able to work and play on the same tablet.

While Windows 8 is not quite in a state where it is ready to be released to the public, it is a completely different beast than the Developer Preview Microsoft released more than five months ago. During a meeting with Microsoft executives, I was told that the Consumer Preview version of Windows 8 includes tens of thousands of changes compared to the version that was released to developers in September. Thousands of changes are system-level items that I’m sure I didn’t notice, but thousands more are user-facing changes that have helped improve the user experience dramatically.

One of my favorite features is the implementation of swipe gestures. As can be seen in the second and third images within our Windows 8 screenshot gallery, Microsoft has tweaked the main menus used to navigate the OS and perform a variety of key functions. While using a touchscreen to interface with Windows 8, these menus are opened using gestures.

A swipe from the bezel around the screen in from the right opens the start menu, which includes a search button to search for files and apps, a share button to share the current page via email or using other services, a start button, a devices button that lists devices connected to your PC, and a settings button that provides quick access to basic settings such as brightness and speaker volume, as well as a link to more system settings. A swipe in from the left switches between open apps, and a swipe in from the left and back out to the edge of the display opens the app-switcher. Within an app, a swipe down from the top or up from the bottom opens app-specific menus.

While using a keyboard and mouse, gestures from the sides are replaced by keyboard shortcuts or mouse touches to the corners of the screen. A touch to the top-right or bottom-right corner mimics a swipe in from the right and opens the start menu while a touch to the top-left or bottom-left corners opens the app-switcher.

There are countless other great features new Windows 8 Consumer Preview; from picture password, an enhanced security feature that lets the user unlock a PC by tracing preset patterns on an image of his or her choosing instead of using a simple alphanumeric password, to “roaming,” which automatically syncs settings, apps and other data between different Windows 8 computers. While one convertible slate can handle duties as a tablet, notebook and desktop computer, Windows 8 is all about choice. Some users may opt for a single device while others will want a lightweight 7-inch ARM-based tablet in addition to an eight-core beast of a desktop PC.

In terms of performance, Windows 8 exhibited the smoothness and stability we’ve come to expect in a post-Vista world, and this is just a preview version. There were hiccups, of course, but overall the experience was vastly superior than it has been with any other version of Windows. The setup is remarkably fast and easy, touch responsiveness is iPad-like and I was quite impressed with the versatility of this platform. To understand the concept of one device for work and for play is one thing. To sit in bed hopping around lightweight apps and then walk over to your desk, dock your tablet, and have desktop-grade productivity software running on the same device is something else entirely.

The machine I tested Windows 8 on is a pre-release dockable Samsung tablet with a 1.6GHz Intel Core i5 processor and 4GB of RAM. Yes, it’s a tablet with a fan. It’s also a tablet that can run your existing desktop-grade enterprise software, consumer software and lightweight Metro-style apps. Get over it.

The Endgame

Windows 8 gives us a glimpse at the future of computing, but it’s not quite there yet. While the version I spent time with is merely the Consumer Preview and not the release build of Windows 8, it gives us a very good idea of what Microsoft’s new operating system will look like when it launches. The concept is fantastic and I very much like Microsoft’s execution thus far, but it still feels like a marriage of two completely different operating systems rather than a fusion of two experiences.

This is by design, in part. Because the function of a true PC varies so greatly from the function of a media tablet (as we know this category of devices today), Microsoft has created separate experiences for each category. There is a tablet experience with the fantastic Metro UI, a desktop experience reminiscent of Windows 7, and a bit of overlap with each, intended to create some amount of cohesiveness. The end result, however, is not a consistent experience.

There is a disconnect that can be felt across Windows 8. Again, this is mostly by design. In what I call “tablet mode,” the user is presented with an interface that is quite clearly built to be touched. It is characterized by a cascade of large tiles that display live data and can be poked to open apps. The Metro-style apps that are revealed house nice big buttons and a touch-friendly design. Metro-style apps also take up every last pixel of the display, which is a fantastic canvas on which developers can paint terrific experiences.

In “desktop mode,” Windows 8 has the look and feel of Windows 7. In fact, it basically is Windows 7. There are some elements of Metro that spill over into desktop mode — such as the app-switcher and Windows Phone-like lock screen, which displays notifications from up to five apps — but they are effectively completely separate platforms.

Desktop mode has not been optimized for touch at all. In fact, tapping in a text field while no physical keyboard is attached to the tablet doesn’t even bring up the virtual keyboard. Instead, the user must tap on a small keyboard icon in the task bar to open the keyboard, and then he or she must tap another two buttons to close the keyboard once finished typing. And while in desktop mode, by the way, I found that the keyboard often obscured the text field in which I was typing.

Perhaps I can better illustrate my point about the disconnect with this simple example:

Windows 8 ships with two completely separate web browsers. One is called “Internet Explorer”. The other is called “Internet Explorer.”

Internet Explorer is a fantastic Metro-style browser that is designed with touch in mind. Controls are large and easy to poke, menus retract and let web pages occupy every inch of the display, and pages load lightning-fast in this lightweight tablet browser. Then, in desktop mode, users can browse the web using Internet Explorer, the same robust web browser hundreds of millions of people currently use around the world on their Windows PCs.

Confused yet?

Microsoft’s inclusion of two completely different web browsers that share the exact same name is indicative of the separation present in Windows 8. One tablet OS and one desktop OS, together on the same machine.

In the end, this disconnect is probably a good thing for now. Windows users come in all shapes and sizes, and millions of people who will upgrade to Windows 8 in the coming years will be terrified of doing so. They are used to Windows as we know it today, and the look and feel of Metro is a complete departure from the Windows they currently rely on day in and day out. After the initial shock wears off, these people who are so scared of change will find themselves eased into the new Windows because desktop mode is so familiar, and because “tablet mode” is so separate from it.

But this is not the future of post-post-PCs.

Windows 8 is the tip of the iceberg. The start of a shift that will eventually see the “tablet” UI and the “desktop” UI merge into one comprehensive user experience. Apple is taking a different approach; as we’re seeing in OS X Mountain Lion, Apple is slowly readying its desktop user interface for a touch environment by taking some of the elements from its gorgeous mobile UI and adapting them for desktop computers. This varies dramatically from the path Microsoft is taking with Windows 8, but the endgame is the same: one experience that is as capable as it is versatile, and as user-friendly as it is beautiful.

This is the future of computing.

Microsoft’s Windows 8 Consumer Preview will become available to the general public on Wednesday as a free download with an initial cache of more than 100 apps in the Store, all of which will be free during the preview period.