Well, if you want to be able to use your monitor, you need a video card.
And the 8800GTS and 8800GTX are already out, they support DirectX 10, so I can't see any reason not to get one just because DirectX 10 isn't out yet. It's not like it won't work with DirectX 9. Another thing - DirectX isn't the almighty power of the universe, it really isn't that big of a deal. Direct3D and OpenGL are just libraries that allow a program to send instructions to the video card. The part about a game that makes it look good are the instructions being sent, not the method at which they are being sent.
Crysis isn't going to look good because of DirectX 10, it is going to look good because it uses a very sophisticated rendering engine, which sends instructions to the video card that make the video card render a realistic image.
All the screenshots and videos we've seen of Crysis so far have been DirectX 9, and when it comes out, it is going to look fantastic on DirectX 9.
So go buy your 8800GTS or GTX and play your games and just rememeber that DirectX 10 is not the almighty power of the universe.