TrustedReviews have looked at the Intel Core 2 Extreme QX6700 (Kentsfield Quad Core)

Intel's approach does have its benefits though. For one, by having all four cores in the same package, there is only one heatsink. Any boards that currently support Core 2 Duo, will support Kentsfield as well. In saying that, we had to update the BIOS on our Gigabyte 965P motherboard, in order to get it to boot. It also makes designing a decent motherboard a lot easier, and means we can expect to see quad core hitting the MicroATX platform.

Intel Core 2 Extreme QX6700 (Kentsfield Quad Core) Review