ATI has already announced a R600PRO based card clocked at 600 MHz for its FireGL range, but as far as we know the HD 2900 PRO card will end up with 160 Shaders and half of the ROPs.
The Radeon HD 2900PRO will end up with 160 Stream processors, 8 ROPs, 16 TMUs and a 256 Bit memory interface.
The Texture Memory Units are the week spot of the R600 design and ATI didn’t reduced its number which will sure come in handy.
The rest of the 160 Stream processors are simply disabled as well as additional 8 ROPs.