These processors will use the new Socket P and will be based on the Merom XE processors.
There's the 2.6GHz Core 2 Extreme X7800 and the 2.8GHz X7900.
The X7800 arrives in the second or third quarter of this year for $795 and will have a 800MHz FSB and 4MB L2 cache. Specifics about the X7900 aren't available yet.