I gave a talk at the Fall 2008 Utah Code Camp going over the information that’s been publicly released about Direct3D 11. Direct3D 11 will be first available in the November 2008 DirectX SDK. When that is released, I’ll be able to talk more about the features in Direct3D 11.
For now, you can look at the slides for my code camp talk, which are mostly cribbed from presentations at GameFest 2008. (Again, not all the details of Direct3D 11 have been made public yet.)