I was blown away when Microsoft's Brian Roper plugged his new Lumia 950 smartphone to a computer monitor and Windows 10 appeared.

It was technically the mobile version of Windows 10, but you couldn't tell at first glance. It was being up-scaled by Microsoft's magic feature, called Continuum, to look like a normal desktop operating system.

Roper opened the iconic Windows Start menu, he used Microsoft Office apps like Word and PowerPoint, he played a 1080p trailer of Jurassic World, he opened the multitasking window where it shows the open apps he was running, all while using a keyboard and mouse.

These are all things I can do on a regular smartphone, except Roper did it on a bigger screen that's easier to see while using a keyboard and mouse that's easier to use, like on a computer.

Microsoft is on to something.

I find myself doing almost everything on a smartphone, but there are certain things that simply require the convenience of a large screen and multiple open windows. For example, I know there are flight-booking apps for smartphones and tablets, but I simply can't research my flights on a small screen. I need the full website with my calendar clearly visible on the side.

And then there's work. There's no way I could work on a smartphone's small screen and limited operating system. iOS 9 on the iPad Pro might show me two full-size mobile apps, but I have seven open on my work computer screen right now. And can you imagine writing this post with a phone's tiny keyboard?

That screen on the left is coming from Brian Roper's phone. It looks like a regular computer running Windows 10. Microsoft So, I need a laptop for those times when a small screen and a mobile operating system just isn't enough. That's another device to lug around. Another device to sync with. Another device to spend money on.

But Microsoft showed us during its event that you could connect your phone to a monitor/keyboard/mouse combo and use it just like a computer. Essentially, our smartphones could be the only device we need.

Of course, it's not the be-all and end-all solution.

It would take some time for us to adjust to a new style of computing. At the moment, no one has little stations with display port adapters, monitors, keyboards, and mice dotted around the places they go most often. And there aren't many places, if any, where you can simply come in and hook up your phone to a convenient adapter/monitor/keyboard/mouse setup, either.

Maybe in the future we'll find physical locations where we can do that. It'll be the internet cafe 2.0.

Roper holding the Microsoft Display Dock, which lets you connect the Lumia 950 to a monitor, keyboard, and mouse via USB-C. Microsoft It would also take time for tech to catch up because phones aren't quite powerful enough yet to run full desktop versions of operating systems and apps, which some might need for more resource-hungry tasks. And they're not powerful enough for proper, multi-window multitasking.

And the "computer phone" won't replace laptops when we need screens in places where we they're not available, like outside in a park, an airport, airplane, or train.

So, there are a lot of obstacles before a smartphone could replace all your computing needs. But at least Microsoft has created a new category. The age of the smartphone is just beginning. Soon, they'll be ultraphones and give us everything we need.