@Soviet176
No if the card supports DirectX 11 it will work with DirectX 10 they are backwards compatible DirectX 11 is just an excuse for something for Microsoft to release it has practically no changes worth noting.
I'm sure it will be fine a more major update may cause issues but DirectX11 is really bugs they wanted to fix from DirectX10 and a few cleaner graphics.
@speed monter
To your yet to appear message, no the X9 packs work with DirectX 10 there are a few that have issues but about 90% work.
Windows 7 Pro, Intel Core 2 Duo 2.8Ghz, 4GB DDR3, Dual nvidia SLI 9600GT 1GB, 1.5TB Hard disk