QX9770 bottlenecked by CF 5870's?

Fallout 3 and Farcry 2 both play pretty well on my single GTX 260 with Q6600 @ 3.2Ghz, @ 1920X1080. Just installed a second GTX 260 and haven't tried them yet with SLI.

I'd imagine a single 5870 would play those games pretty darn well, let alone two in Crossfire. With the price on the 5870's, were it me, I'd buy a single card and pick up a second one 6+ months from now when the price comes down. Almost no need for two of them right now I'd think.