Usability 
A set of pages demoing the use of HTML5's video, audio and canvas elements a comprehensive test suite covering 160 HTML elements and capabilities from mobile development shop Momac. I ran the test on a bunch of mobile browsers with the following results:
Android 2.1 - 118 (out of 160)
Skyfire 2.0 (Android) - 110
Bolt 2.1 - 99
Opera Mobile 10 - 33
Skyfire 1.5 Symbian - 18
Opera Mini 5 - 14
UCWEB 7.2 - 4
Nokia N95-3 Webkit - 0