This is, to be clear, just the desktop version of Flash 10.1—the full-fledged Flash for Android, webOS, BlackBerry and Windows Mobile is still a ways down the pipe. It's worth getting excited over anyway, since I've watched an HP Mini 311 with an Ion graphics chip tear through an HD YouTube clip without breaking a sweat. For now, graphics acceleration is limited to Windows, unfortunately. But still, perfect timing, really, since YouTube's launching 1080p video this week (perhaps not so coincidentally).
The new version of AIR acts more like a native app, with full support for mass storage, multitouch gesture support, communication with actual native apps, and access to USB peripherals, p2p networking, and faster WebKit rendering, among other perks for developers. Maybe I'll stop hating it so much now.