AMD seems to be planning another mainstream graphics card. This time it'll be the non X mode R9-280. The R9 series is based upon the 28 nm "Tahiti" GPU (Radeon HD 7950). The chip would feature 1,792 stream processors, 112 TMUs, 32 ROPs, and a 384-bit wide GDDR5 memory interface, holding 3 GB of memory. AMD is looking to release this card in a competitive sub-300 USD price segment.
Other then that there are no real specs but you can assume clock frequencies above 850 MHz on the core with roughly 5.00 GHz (GDDR5-effective) on the memory.