Highlights include up to 20% faster scrolling, H.264 video decoding at 30FPS, and GPU-accelerated animation or gaming at up to 50FPS. Greater gesture support has also been rolled in, plus Bitmap Capture for StageWebView for tighter HTML and Flash visual integration, and Asynchronous Bitmap Decoding, for improved image transitions.
The AIR 2.6 SDK is also on target for a H2 2011 release, but apps developed with the 2.5 SDK will of course run fine with the AIR 2.6 runtime.
Overall, not a bad and timely update, bringing AIR support to the incoming Honeycomb tablets. If you haven't installed AIR on your Android device yet, considering there are loads of Android apps that require AIR to run, perhaps now is the time to see what it can offer you. A list of Android devices that support the requirements of AIR can be found here.