The Inquirer has some information on the long awaited NV30 from nVidia.

What we haven't yet mentioned is what kind of memory it sports and what is the actual clock speed of it. That’s where the surprise comes in. Assuming that the NV 30 would use standard DDR memory was a big mistake. The NV 30 will use DDR II memory, the (r)evolutionary memory marchitecture. But there's even more.