Nordic Hardware claims Asus and DFI managed to fix support for quad-core Intel Penryn processors on their nForce 680i based motherboards:
Since a few companies have their own layouts, like DFI and ASUS, they decided to get to work on the retail quad-core Penryn support with their nForce 680i boards. And they seem to have solved it. Both DFI and ASUS have beta BIOSes with working retail Penryn support for their nForce 680i-based motherboards DFI LanParty UT NF680i SLI-T2R and ASUS Striker Extreme. It's unclear when these BIOSes will be available to the public, but it shouldn't take too long.