An i5 750/760 and SLI will do wonders. If you will be primarily gaming most games don't even use HT which is the only advantage of the 8xx i7's (aside from clock speed, which can be evened out by overclocking). Plus the higher turbo of of the lynnfield CPUs is an added benefit in mild OC's (When compared to x58).
I was in the same boat before I built my current setup and I came to the conclusion that for my primary use, which is gaming, the P55/i5 is perfect. x58 is if you wanna get the maximum performance, or do a lot of video editing, but you will pay for it. And as has been said before, the 480 only loses about 1-3% in an x8 slot, I think by the time you buy the equivalent of over SLI 480's it will be time for a new setup anyways, if you continue buying the upper midrange cards that is.
Either way, I think you will be impressed by your SLI performance.

I agree with thetacowarrior...
 
This is what I would get for gaming...
 
i5-760                                         $209.00
 
ASUS SABERTOOTH 55i                $158.50
 
CORSAIR XMS3 2 X 2GB 1600        $72.00
 
CORSAIR TX750W                        $100.00
 
TOTAL:                                      $539.50
 
 

Well, if I am spending that much on a x55 board, I might as well get the X58 Sabertooth for $199. Don't you think so, and even though x58 is becoming replaced with a higher-end one later next year, I am at least a bit more "future-proof" (whatever that means in a 6 months cycle!). Don't you think? :)

sweet as dude let us know how its going fire up old bc2 and see how she runs 

So far so good! I swear, I can notice that everything in Windows 7 x64 Ultimate, (compared to the same settings under AMD) seems snappier!
 
I traded my old AMD CPU, MoBo, and RAM and paid $248 in difference. (the price includes a $20 OEM SATA DVD-Burner, 6GB XMS3 DDR3 upgrade and of course i7 Core 950 and X58 Sabertooth!)  I know, it is crazy!

Not, yet. I am about to install some games!