It's been first discovered in a driver INF file that ATI are prepping up a Radeon HD2900Pro graphics card, which would be much welcomed given there is quite a big gap in price and performance between the HD2900XT and HD2600XT.
Though this isn't made official yet, it's fairly logical to see one arrive sooner or later.
More details over at the Inquirer.
IT SEEMS THATTHE HD2900 family of products will probably expand from current one official and one dark horse chip with at least one more member.
The original plan that ATI had for the product line called for four members of the family: 1GB GDDR-4, 512MB GDDR-3, 512MB GDDR-4 and 256MB GDDR-3 models, and four different PCBs were developed. We all know how that ended, with AMD execs promising a hard launch of 10 products and then delivering two, abandoning the 1GB model for retail and delaying the HD2400/2600 to summer.