Yup, it will run, it will just may be bottlenecked depending on what rez you play at and what card you get. 9800gx2 or faster is bottlenecked, at least at 1920x1200. That's from my own personal experience and testing.
I game at 1920x1200 and I have both a GTX280 and a DFI LP UT P35 motherboard which is NOT PCI-E 2.0
Am I being bottlenecked by this config?