Android has evolved more aggressively, more rapidly than any other mobile platform. But now it's reached a point of maturity, and you can see that in Gingerbread: The newness in Android 2.3 is all about refinement. Not new features or functions or just stuff. It's Android where Google's slowed down and taken the time to think about how it looks and feels and responds.
The irony, of course, is that most of the careful design work that's gone into Android 2.3 won't ever be seen by a large portion of Android users. The definitive Android design won't be experienced by people who own phones covered in custom software. There's only a handful of Android phones in the US where you'll be able to get the real Android experience - Nexus One, T-Mobile G2 and the Nexus S - even though it's unquestionably better than anything phone makers are conjuring up themselves these days.
The core Android experience is largely unchanged from Android 2.2: everything works just about the same. What's different? It's smoother, faster and for the first time, it feels like one person actually designed the Android interface. There are details! The orange glow when you hit the end of a list. The old boob-tube-style shutoff whenever the screen turns off. They're little things, but they add up to a phone that just feels better - even when the occasional rough spot still pops up in Android (and they do). And half the battle with an interface is making it feel great. (This is why, for all its flaws, people dig Windows Phone 7.) The speed improvements over 2.2, while subtle, make a difference. It's the first time Android's really approached iPhone 4-level responsiveness. On the other hand, it's somewhat unreal it's taken over two years to have the finer things in smartphone life on Android.
Speed, speed, speed. Still loving the new hyperflat, orange-and-green-and-black interface after several days - it makes me think of Tron. Things like the Downloads app to collect everything I've downloaded. The new keyboard doesn't make me want to drill my fingers through the glass anymore. Android is still the most connected-feeling mobile OS around, by leaps and bounds. Major components - like Gmail and Maps - are broken up so they can be updated individually instead of having to wait for the next major OS push.
Still a little too confusing and PC-like for some people, even if it does look spiffier. The Market's not much better to dig through. No native video chat! Crazy! Especially considering that Google's got Google Talk and that the new definitive Android device has a front-facing camera. Android media experience is still pretty weak compared to the iPhone, from getting music on there (sorry, drag and drop is not media management) to the better-but-still-mediocre music player (just because I can download WinAmp doesn't excuse Android's native app's suckage).
Android 2.3 is almost exactly where Android needs to be to take the next step: the fundamentals, the vision, the polish (mostly) are there, finally. Now it's time for all of the amazing things Google's promised next.