Over the past 24 hours I’ve seen a lot of words thrown around about Windows 8, ecosystems, operating systems, and what should Apple do in regards to Microsoft’s all-in-one attempt to deny the post-PC era altogether by unifying PCs and post-PC devices in a single OS.

There’s some great commentary about this already out there. What I’d like to briefly touch upon is this: does Microsoft’s approach with Windows 8 confirm a somewhat popular argument – that Apple is ultimately breaking, not unifying, the experience with the distinction between iOS and OS X?

It’s easy to look at the issue from such a perspective. If Windows 8 runs on all devices – let’s pass on Windows Phone 7 for smartphones – then that’s most definitely a real ecosystem, not Apple’s. As iOS and OS X are two different operating systems (different distribution methods, installers, frameworks, GUIs, native apps, names) running on at least three different form factors (the phone, tablet, and laptop), Apple’s “lock-in” strategy comes out defeated in the confrontation against Windows 8.

I don’t want to argue on which OS is “better” (a definition that doesn’t even make sense, right now) or which one will sell more copies; rather, I believe there are a few key areas that several early commenters of the Windows 8 Developer Preview failed to highlight.

In Apple’s vision, separate operating systems can live inside the same ecosystem. The single defining aspect of this vision is the Apple ID, which on iOS devices, Macs, PCs, and web browsers gives you access to:

• Songs, Movies, TV Shows, Books, Podcasts;

• Apps;

• The Apple Online Store;

• Your iOS device’s location (still free with MobileMe);

• Email, Calendar, Contact and data sync with MobileMe;

• Your desktop operating system (with Lion’s Apple ID support).

For as much as it’s difficult to keep this all together with a single Apple ID, that’s what it does. Soon, Apple will introduce iCloud to overhaul MobileMe’s syncing capabilities and turn them into seamless pushing of documents, data, and media across devices.

In fact, you may remember Steve Jobs demoted the Mac to just a device back at WWDC. Why? Because the Mac isn’t more “important” than an iPhone or iPad anymore. The ecosystem (and iCloud is a big part of that) is what matters now. Yet this vision doesn’t imply multiple OSes mean separate ecosystems: iCloud is one, and it works on iOS, OS X, Windows PCs, and the web.

Sign of Apple’s appreciation of a single ecosystem can be found in the iWork suite, the Apple Online Store, and even Ping.

In this context, Apple’s strategy isn’t too dissimilar from Microsoft’s. After all, Redmond has got its own set of web platforms, too, and Windows 8 will feature an App Store and other kinds of tablet/PC integration. But there is a key difference that some people, when comparing Windows 8 to “Apple”, surprisingly omit: based on what we’ve seen (that is, the first, incomplete, buggy Developer Preview), Apple’s ecosystem strategy is nothing like Microsoft’s.

Apple wants to build a single ecosystem by keeping its OSes separate. They want to do so because they believe the similarities that keep the ecosystem together are equally important as the uniqueness of each operating system – its strengths and virtues and hardware features.

Today I asked on Twitter: Would Apple fans applaud an iPad that runs both iOS and OS X? By far, the response was “no”. The reason’s simple: iOS was built with multi-touch in mind, whereas touching a Mac’s screen is still awkward (and doesn’t work). In its very own nature, OS X works with clicks and drags, not taps and swipes. Lion epitomizes Apple’s intention to enable some kind of deeper touch interaction with Macs sometime in the future, but the fact still holds true: you can’t touch OS X. iOS and Lion look similar in order to carefully transition the users from a platform to another in the ecosystem stream, but they’re unique and true to their own interfaces, interaction schemes, and destination hardware.

You will be able, however, to touch Windows 8 on a tablet. Or to scroll Windows’ Metro with a mouse wheel on a desktop PC. And here’s where I believe Apple and Microsoft, ultimately, diverge: Apple is creating an ecosystem that works with multiple OSes, provided these OSes run on the devices they belong to. For Microsoft, on the other hand, Windows itself is the ecosystem, and that has to be integrated on every device. There is a subtle difference between ecosystems and OS uniqueness, and you’ll be the judge of which strategy will win over the other two years from now.

There are several ways to build an ecosystem. I don’t know if I’ll like Microsoft’s one, but I’m sure there will be both subtle and key differences to consider when comparing it to Apple’s future strategy.