We have found out that only three third party memory companies actually have DDR3 in their hands. You can get some from Kingston or Corsair. There might be some smaller players that might have some of this memory but all of the modules out in the wild still work at the default speeds.
It is still too early for overclocking these modules as DDR3 boards are still not out. The DDR 3 will get more important around Computex time as Intel plans to have at least two chipsets out that can support this new memory. We are talking about P35 and G33 chipsets, and we saw a lot of motherboards back at Cebit.
In the mean time you will have to stick to DDR2 and 1280 MHz is the best we could find.