The regular OS X the backbone of everything Apple these days. It's used across the board on all of Apple's hardware.
Mac. iPad. iPhone. iPod Touch. And even Apple TV.
However, it's the iDevices that is getting the bulk of the attention these days. It used to be that when new Macs are freshed, websites trip all over themselves trying to report on the specs, benchmarks, and any changes in the exterior aesthetics. Sure, we love a looking Mac these days but with the Macs in parity with the PC computers because of the Intel chips everyone pretty much use now, there just really isn't a lot to get excited about.
Now, it's the iDevices that hold the backbone of Apple's growth engine. The iDevices are Apple's ambassadors to the world to convey what Steve Jobs see the future of computing, entertainment, and content distribution should be like.
With it, it'll be the iPhone OS that will be the differentiating factor. Development on OS X will continue because Macs are still an important part of Apple's business. But any new innovation in the core of OS X will likely be shared with the iDevices. And on top of this, Apple engineers will work to improve the mobile experiences iDevice fans have come to expect.
I'm bring this up now because WebOS is still around while RIM is about to introduce Blackberry OS 6. Meanwhile, Windows Phone 7, very very delayed, should not be discounted (remember how Steve likes to remind us about those copiers that Redmond has to copy Mac OS features?).
And Apple's greatest competitor today appears to be Google. And Google is firing on all cylinders. In fact, it's adding new cylinders all the time. It's partner with Adobe to bring Flash into Chrome and Android even as it continues to work on HTML 5 features. Furthermore, Android 2.2 was just introduced today, bringing it ever so much closer to matching iPhone OS.
Android Competition. I hope, and I'm confident this is the case, that Steve and Apple know that Google is a different kind of competitor that Microsoft is in the las decade. Google is just as capable of innovation as Apple is (san a visionary like Steve) with a completely different take on mobile.
It's important for Apple not to think simply it can out-innovate Google. iPhone OS that powers the iDevices is the key to everything at this point. In 1984, it "thought different" with the Macintosh. In 1997, Apple thought different with the iPhone.
It's time for Apple to "think different" with the iPhone OS and change the dynamics of the mobile landscape again.
Personally, I'm glad there is a Google that is pushing Apple team so hard.