Intel said at the Game Developer Conference in London today that it's also planning a 2.4GHz version of the quad-core Core 2 Quad (Kentsfield) processor.
We haven’t seen a 2.4GHz quad part on Intel's recent roadmaps but we have to trust the company representatives. It should come, eventually.
We also learned that these Quad CPUs are scheduled for the launch in the middle of November, we could not get more exact date. We saw the 2.4GHz part up and running but I guess that the possible clocks will depend on the yields on these Quad cores.
We also learned that they are quite useful in game programming but we will come to that with more detail part.