CSS3 support is there but without too much digging I don't know if this is an MS implementation or if they have followed standards (suggestions on a postcard please) but given the commitment to SVG, which is a direct competitor/replacement to Silverlight and Flash it's likely the browser devs are actually listening to users.
On the edge of the blade side of things we see the IE engine using the Direct2D API's to offload graphical processing tasks to a compatible GPU; a nice touch. They have also added some neat new DOM events and objects and support for a multitude of HTML 5 goodness although we don't currently have evidence of the <canvas> tag support everyone is looking for, here's hoping eh?
If you want to give the preview a shot and check out the differences between it and MS's old browser engines (IE6 - 8) then click below:
If not then, like me, you already have a better, more compliant browser which you are probably using to read this. But still, kudos to MS and the IE team, keep up the good work.