A few years ago, the Firefox fanboys were arguing for Internet Explorer to drop its own Trident rendering engine, and adopt Firefox's Gecko engine. More recently people have argued for Internet Explorer to use Webkit. Looking at these results, shouldn't we be asking Firefox and Chrome to use Trident? Well no, but it's the thought that counts.
As we can see above the Platform Preview of Internet Explorer 9 passed all 192 of the tests co-developed with the W3C, no other browsers came close. Other browsers like to claim to be standards compliant, but which standards and what does that really mean? It means not using proprietary tags (like Firefox and Webkit browsers) and not trying to roll out standards before they're finalised (like everyone did with CSS2).
So not only is Internet Explorer 9 really fast thanks to being GPU accelerated, its HTML5 and CSS3 support is shaping up nicely for when the time comes and they are finalised.