One more reason to use Google Chrome or Firefox! (sorry, I support Microsoft, just not their desktop web browser. Still has lots of catching up to do with Firefox, Google Chrome, and other HTML5-compliant browsers that conform to W3C standards completely)
The W3C has not finalised HTML5 yet, and won't for a long time. Gecko, WebKit, even Presto all deviate from the provisional published specifications in some way already anyway. Trident's conformance level with the draft HTML5 and CSS3 specs has absolutely nothing to do with the stability and correctness of user chrome code.