If you use an iPhone, iPad or Mac, Monday is the day everything changes.

At 10 a.m. local time, an Apple executive — probably CEO Tim Cook — will trot onstage at San Francisco's Moscone Center to kick off the keynote for the company's annual Worldwide Developers Conference to unveil the next generation of software for all its devices. iOS 8 and OS X 10.10 will be shown to the public for the first time, each with plenty of new features.

The software won't actually arrive on consumer devices for months, but the event will point the way for Apple users everywhere. Will Apple wow us with innovations, or will it be complacent with just incremental updates?

Plenty has been rumored already, from a new health initiative to a major desktop redesign. Apple has also recently grabbed more than its typical share of pre-show headlines, thanks to a timely acquisition of Beats. Don't expect a lot said about that at the show, however — the deal has yet to be finalized — but we may see a cameo from Dr. Dre or Jimmy Iovine.

What we can expect are the full skinny on the new versions of iOS and OS X. Here's what Apple (probably) has in store for us at WWDC 2014:

iOS 8

The new version of Apple's mobile software, iOS 8 (confirmed in photos), likely won't be as big of a leap as last year's jump to iOS 7. Apple did a complete design overhaul last time, while at the same time adding game-changing features such as Background App Refresh — that's a tough act to follow.

Apple’s iOS 8 banner! Any sleuths out there want to pick it apart? pic.twitter.com/kql5X3PQcv — Steve Kovach (@stevekovach) May 30, 2014

That's not to say all Apple will be doing is crossing t's and dotting i's. Apple will debut some major features in iOS 8, and we'll be able to see where the company sees mobile technology going through its initiatives.

Healthbook

If you own a smartphone, chances are you probably have at least one running app, pedometer, sleep tracker or dieting app in there somewhere. Many people have several. Now Apple appears to be on the verge of creating its own, an app/hub called Healthbook.

A report from 9to5Mac described Healthbook in detail, indicating it would be capable of recording steps taken, heart rate, hydration, nutrition, blood-sugar level and other factors. Each one of these would exist as a "card" within the app.

The iPhone 5S has an M7 motion coprocessor that's capable of capturing a little of that data (mostly steps), but most of the cards would need to get body information from third-party apps and devices — leading to the conclusion that Healthbook will likely function more as a centralized hub for fitness apps rather than Apple's own attempt at one.

There's another possibility: that Healthbook will work in conjunction with the rumored iWatch, which theoretically would have the sensors needed to get all that data. Since Apple typically doesn't debut major mobile hardware at WWDC, that could mean Healthbook won't arrive until later in the year, or a more basic, watered-down version is in store for Monday.

Maps update

Ever since its botched debut in 2012, Apple has been furiously improving Maps, which now isn't half bad. Based on acquisitions and rumors, Maps will finally get directions for public transit. It'll also get better points of interest (POI), including airports, parks and highways, according to 9to5Mac.

Split screen for iPad

Both Windows and Android (at least some devices) can display two working apps onscreen simultaneously. While the iPad lacks this feature, Apple may be planning to introduce it in iOS 8. That would greatly enhance the tablet's use as a platform for productivity, although the feature is reportedly not ready to be unveiled at WWDC.

Siri improvements

Image: Apple

With every version of iOS, Apple squeezes in some improvements to its voice assistant. While it's a given Siri will get more tie-ins with some lucky third-party apps, it may also pick up a few new abilities now that competitors such as Microsoft's Cortana have shown the value of people reminders and "proactive" assisting, such as telling you the weather every day instead of waiting for you to ask. Developers may even finally get a Siri SDK.

Wild cards

OS X has interactive notifications — that is, notifications you can respond to without having the app open — so why not iOS? That could be coming in iOS 8, along with a standalone app for iTunes Radio. Multiple user profiles for iPad has long been a demand; is this the year Apple finally gives in? And an iCloud update that grants free iPhone and iPad backups, and automatically syncs videos into Photo Stream, would be most appreciated.

OS X 10.10

Whereas last year saw iOS get a major redesign, this time, it's OS X's turn. OS X 10.10 (which, yes, makes no sense mathematically) will be called either Yosemite or El Cap, based on banners on display at the Moscone Center, and will feature a design overhaul, according to rumors.

New design

Apple's desktop and mobile platforms have never looked more different. When iOS ditched textures for flat design in iOS 7, OS X took a few of those cues, but it didn't go nearly far enough. System and app icons still look very textured, and the "layering" of windows over backgrounds — which looks great in places like Launchpad — could use more of a presence.

At the same time, the basic UI of Apple-grown apps such as iTunes, iPhoto and Aperture is long overdue for a refresh. Other music services, including Xbox Music and Google Play, have shown how well a strong visual UI can work, while Adobe Lightroom completely outclasses the experience in Apple's photo apps. It's time for some more spice in the iLife.

AirDrop to iOS

OS X has a feature called AirDrop. iOS has a feature called AirDrop. Why don't they work with each other? This problem should be high on Apple's list to correct in OS X 10.10.

Even better multi-monitor support

OS X 10.9 Mavericks was a giant leap forward for multi-monitor support, but users still complain of waylaid windows whenever they detach and reattach a Mac. OS X 10.10 will hopefully include some help — such as a quick, obvious way to reel in all of an app's open windows — if not a fix.

Siri arrives

Apple had been expected to roll out Siri on the Mac in Mavericks, but that never happened. Now that Google has begun squeezing voice search wherever it can (it even recently came to Google Maps on iOS), Apple may finally have the incentive it needs to bring Siri to OS X.

Wild cards

Apple could surprise with an unexpected feature such as built-in support for 3D printing, easier exporting of iTunes playlists to other services, or even iTunes for iCloud — which would enable playback of iTunes content through a web browser — but that's all probably wishful thinking. What might not be so wild, however, is the prospect that OS X 10.10 could come to users early through the beta program, which Apple recently opened to the public.

Smart-home initiative

Last week, the Financial Times published a report that said Apple would roll out a new smart-home initiative at WWDC. The rumored system would provide a way for developers to easily integrate their apps in a centralized hub, letting users control multiple home appliances from an iPhone, all with a consistent user experience.

A subsequent report threw some cold water on that rumor, however, saying Apple's supposed smart-home initiative was actually just a certification program. Manufacturers could apply for a label (similar to "Made for iPhone) as long as their products meet certain criteria. Apple may not be moving too deep into the "Internet of Things," after all.

iWatch and other Hardware

WWDC usually isn't the time for new hardware — at least not mobile hardware. The past two years, Apple debuted the Mac Pro (2013) and the MacBook Pro With Retina Display (2012) at the conference. But considering the lack of credible leaks in the lead-up to this year's show, 2014 could be the year there isn't a notable hardware release.

Sure, there have been the usual rumors, the most tantalizing of which is the possibility of a 12-inch MacBook Air With Retina Display. But considering Apple just refreshed the MacBook Air line, that machine probably isn't ready for an unveiling — if it exists at all.

A new Apple TV has also been rumored, but that seems unlikely, too, especially if Apple's smart-home plans end up being a dud (a new, enhanced Apple TV was rumored to act as a smart-home hub). In any case, considering Apple still views the device as a "hobby," it's hardly a headline gadget.

One of the many iWatch concept photos making the rounds online. Image: Todd Hamilton

Everyone expects Apple to release an iWatch this year, but in all likelihood, WWDC won't be the place we see it. Of course, any kind of fitness initiative or Healthbook app will strongly hint at its existence, but Apple's first foray into wearables will have to wait.

Moving forward

Apple will shake up its software platforms Monday morning, and that will kick off a whole summer where iOS and OS X developers explore the possibilities. When the curtain comes down on the WWDC keynote, it's really just the beginning.