PC Perspective has published a review of the XFX nForce 680i SLI motherboard and tested out its support for the new 1333 MHz FSB Intel processors

A quote from the article:

The only feature missing is support for DDR3 memory which several of the P35 motherboards we have tested use. There is no doubt that DDR3 will be faster than DDR2 at some point, but for now, the performance differences aren't very big but the price differences are! DDR3 is still very hard to find and when you do locate it, be prepared to pay a premium. So, maybe having the 680i chipset with DDR2 support isn't so bad after all.

XFX nForce 680i SLI Motherboard Review - 1333 FSB Support