On Thursday night, after the all-hands party, Matt Woodrow landed a beautiful refactoring of our texture upload code. This should give a noticeable improvement in scrolling performance when accelerated layers are enabled and hopefully fixes some of the problems people were seeing there. It also improves texture upload performance on OS X.
Unfortunately, there are still two bugs that are keeping us from enabling accelerated layers by default:
Bug 619615 - Hangs on Nexus One
Bug 619539 - Startup crashes on Droid
Any help debugging these problems would be greatly appreciated.