FUD Zilla claims Intel's Nehalem processors will not support anything faster than DDR3 1066MHz:
We were surprised to see that the Bloomfield generation of CPUs will officially support DDR3 800 or 1066. Even the extreme edition 3.2GHz Core i7 officially only supports DDR3 1066 and not faster. There won't even be an official support for DDR3 1333 not to mention 1600 or faster.
Fudzilla has already mentioned the fact that for some reason you need to run memory CPU voltage synchronously which might be an overclocker's worst nightmare. At this current stage you cannot go over 1.65V and some memories such as DDR3 1600 or DDR3 2000 might need a bit more than that. With more than 1.65 you will kill any current Nehalem CPU.