Peter-Paul “ppk” Koch writes in his blog, QuirksBlog (which lives on his site, QuirksMode):
In the past few days I’ve been revising the CSS compatibility table with information about the latest crop of browsers. There’s no doubt about it: this is IE9’s show. It just supports nearly everything. No hassle, no buts.
…
Microsoft has finally taken the big leap forward we’ve been waiting for ever since they announced their decision to restart IE development back in 2005.
IE9 promises to be an excellent browser. Its CSS support is now at par with that of the other browsers — although each browser still has its specific areas where it performs less. But we cannot in good faith say that IE is behind the others any more.
In the article, he does a run-down of CSS selectors and finds that the upcoming IE9 does an excellent job of supporting them.
Go take IE9 for a spin – download Platform Preview 3 and try it out – and make sure to try your hand at CSS 3 as well!