Steve Smith, from Intel's Digital Enterprise dept, has been filling us in on some more details about Core 2 Quad.
The QX6700 be a 130W part, which is clearly quite a lot more than the current Extreme Edition X6800, which comes in at 80W - it's more like Prescott, which came in at 130W. Steve said that he expects the power usage for the Extreme part to come down as Intel transitions down to 45nm.
However, there will be mainstream Core 2 Quad parts which come in at more like 100W.
Kentsfield is made up of two Conroe cores on a single chip - not a new, single quad core. The two Conroes will communicate with each other using the FSB. Smith says that this won't cause a performance bottleneck in the real world. We won't see 'monolithic' quad-core, as it's called, until 45nm.
The four cores on the QX6700 will have 8MB of cache in total (2MB per core). The chips are pin compatible with Conroe on LGA775, and any motherboard that currently supports Conroe should be BIOS upgradeable to support Kentsfield.