There is growing information on the Radeon HD 2900 Pro and 2900 GT, however, not all of it is coherent.
For example, HIS has already unveiled its Radeon HD 2900 Pro VIVO whose product page mentions a 512 bit memory interface, while the below document from AMD published by ComputerBase specifies a memory bus with a width of 256 bits. The Pro version Pro like the XT is equipped with 320 scalar processors.

Otherwise, in addition to this information, according to our colleagues at Beyond 3D, the Radeon HD 2900 Pro’s GPU/memory frequencies could be 600/800 MHz. For comparison, the Radeon HD 2900 XT is at 742/828 MHz. The only thing is that in the past ATI sometimes set the final specifications of some of its cards extremely late and these could therefore be subject to change before commercialization. Finally,
geizhalsgeizhals, a price comparison site, already lists the Radeon HD 2900 Pro from GeCube in Germany at 230€.