Directx 10 games

Lately i've been starting to look at parts for building a custom computer, but i am not very educated when it comes to building computers.

So... my question (since i am looking to sli 2 XFX GeForce 7300 GT's) do the newest games (like crysis and those other insanely demanding games) NEED directx 10 to run? Im not a graphics freak, and if the game or whatever is less sharp i won't care a whole lot, im more centered around gameplay.
I know those cards wont support directx 10, but i am worried that the games wont even work on a directx 9 system.

Thank you

hello chjoco, to answer your question so far all the new DX10 games that i know of and that are coming out are also DX9 games . all that DX10 offers is those intense details. but from that and DX9 there isnt very much difrence i personaly am going to buy two 8800 GT's in the near future =)