I think 965 and 975 are the 2 chipsets to support core duo right now.
These chipsets also support C2D from personal experience:
VIA PT880 Pro
I’m sure there are others also. The issue is as much about the VRM as the chipset.
add to the list the i865 and i875 (in theory, don't know of any current mobo maker using the i875 in a core2 duo platform, but the i865 is being used), and the later revison of the ATI xpress200