Out of the pipe even before the hardware has been released; Dirt 2, Battleforge and S.T.A.L.K.E.R: Call of Pripyat will all have DX11 support and Battleforge is already on shelves (actually Free - relatively speaking), so adoption is already ahead of the DX10 release.
Hopefully this new programming layer will allow those with slower systems but more cores to leverage against demands of the newest games being released to enjoy a better experience.