I thought that two 9600GT's in SLi were much more efficient than two 8800GT's in SLi?  Doesn't the 9 Series make much more use out of the 2nd GPU?

According to one of FiringSquad's reviews of the 9600GT, the SLi setup is only marginally lower than an 8800GT SLi setup:



But, seeing that the price of the 8800GT has managed to slowly decline, it would most definitely be the better pick at this point.

Of course the 8800GT is a good card for the price. But the 3870X2 only getting 1 fps better than the 3870 seems a bit wierd, even though the Crossfirex driver hasn't been released yet.

Crysis isn't the best game to test SLI or Crossfire in.

I believe it's more of a "When will Microsoft support it?" question. Doesn't matter for the CPUs which you have. You just have to have support from the OS and obviously the motherboard.