I think because the memory controller's onboard it'll only support DDR3 memory and that's preferably in tri-channel. So it'll means you won't be able to use your DDR2.
Your both wrong Asus P6T FTW! JK really any of the top manufactures board are awesome right now. They all will be using the exact same chipset so really it just comes down to what features you want and how much you are willing to spend.