FUD Zilla claims the first DirectX 11 graphics cards will arrive by the end of 2009, while the first DX11 games may arrive by early 2010.
The launch should probably take place in last two quarters of 2009 and the competition between Nvidia and ATI who might be the first one is on. Nvidia needs DirectX 11 more than ATI, as Nvidia decided to ship the DirectX 10.1 claiming that all the parts of DirectX 10.1 will be included in DirectX 11 spec.
DirectX 11 might be an important step in defining in-game physic as a standard, something that needs to be done by who else than Microsoft. Nvidia will push its PhysX hard and it will be interesting to see what are Microsoft plans with this.