I'm using a quad-core AMD proc oc'd to 3.5GHz.. Since the I7 outperforms it, you should have better results. In Windows7x64, with 8GB Memory, raid5 sas and a pair of ATI 4870 cards in crossfire mode, I run through ISBoxer on two Monitors using ISBOxer for window management (blows away what Keyclone can do, and comes free w/ Innerpsace).

I run the Tank on Balanced Graphics and the other 5 toons run 'extreme performance'. My tank window is locked down to 35fps and rarely drops below 20fps (unless i'm raiding, then all bets are off). The background windows are locked to 20fps and I rarely see them drop below that. I have the Tank and 1 Healer each using their own Core. I then have 2 toons locked to the 3rd core and the other 2 toons locked to the fourth core.

In short, it plays beautifully.