The folks over at the IEBlog just posted An early look at IE9 for developers.
CSS: They explain why they only got 32/100 on the acid3 test: Regarding the technologies that acid3 tests, "many [are] still in the “working draft” stage of standardization". (Editorial: And what? You don't deign to implement things that haven't fully settled down to your satisfaction? You're not getting any brownie points with consumers or developers with that attitude, IE team. Remember the good ol' days when you *invented* and implemented the standards before anyone else? Remember how it was that risk-taking, can-do, forge-ahead attitude that won you the browser war? You won't win this one by waiting for the spec to become 100% final before you dare to touch it.) Then the good news: we've got rounded corners now. CSS3 selectors seem to be coming along swimmingly, passing 574/578 tests on css3.info.
But perhaps the best news?
"We’re changing IE to use the DirectX family of Windows APIs to enable many advances for web developers. The starting point is moving all graphics and text rendering from the CPU to the graphics card using Direct2D and DirectWrite. Graphics hardware acceleration means that rich, graphically intensive sites can render faster while using less CPU."