Nehalem's new CPU socket is bigger and more robust
 

THE NEW, LARGE LGA1366 socket for uni-CPU (Bloomfield) and dual-CPU (Gainestown) 2008 Nehalems is not just 20 per cent bigger on each side than the LGA775 for the current Penryns. It contains nearly 600 extra pins for those QPI links, three 64-bit DDR3 memory channels and, obviously, a lot of power.

It is also seemingly far more robust when it comes to keeping it tight to the mobo.

http://www.theinquirer.net/gb/inquir...es-nehalem-cpu

Will just say I'm glad I never upgraded my CPU waterblock now... :)