Techgage published a bit more information about overclocking Intel's upcoming Core i7 "Nehalem" processors. There's still a lot of uncertainty but the reporter heard from Intel that going beyond DDR3-2000 speeds should be entirely possible as the chipset and CPU shouldn't be the weak link. The ideal memory configuration for a Nehalem system is said to be 3x 1GB DDR3-1066MHz and Techgage also writes it's advised not to mess with the 133MHz figure of the QPI as Intel engineers are unsure what could happen with a highly overclocked QPI over time.
First and foremost, while the 'ideal' memory configuration for a high-end Yorkfield is 2x1GB DDR3-1600, the ideal solution for Nehalem will be 3x1GB DDR3-1066. Seems weak, but if you read my article last night (and I do recommend it), then you'd know that it's far from being the weak link here. It effectively removes any potential bottleneck, and in most regards, the I/O becomes the new bottleneck (one that's not really seen with RAID'ing multiple SSD though!).
How will you overclock memory on Nehalem, or the CPU for that matter? Well, I'll admit I still don't totally understand how memory is overclocked, or how the frequency is even calculated, but Intel stresses that the skies the limit. The chipset and CPU shouldn't be the weak link, rather it would be the modules themselves.
Going beyond DDR3-2000 speeds should be entirely possible. You might run into weird issues which will likely not be visible with regards to strange dividers, but the overall performance really wouldn't reflect it. That's something we'll specifically have to test once the chip hits the lab.
While it's clear that overclockers will need to refresh their skills the reporter believes Nehalem will overclock really well as he has already seen engineering samples running at 4GHz on a modest air cooler.