The C2D's are amazing... I just put an e6400 to 3.5Ghz and what it does for Lomac is awesome... as was stated it's all about the minimum.
I went with a 965, the Nvidia chipsets are LIKELY to perform well and stably, but statistically I wouldn't take the chance. My Intel Asus board (P5B-D) has documented problems with pci-e link going to x1 over certain FSB's, JMicron problems (what board doesnt?,) and some others but they're far and few between....
Keep faith on the competition front, although nothing conclusive, AMD hasn't been resting it seems. http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2939