This post comes inclusive of many grains of salt, but the first leaks on AMD's Radeon HD 7970 are here. The GPU is said to be released on January 10, 2012, where our VGA editor has promised me after he's done he's going to send me all of our samples, right Shane? ;)
Onto the rumor, 3DCenter have a compiled list of specifications for "Tahiti", from various sources and bits and pieces of info from here and there:
4.50 billion transistors, die-area of 380 mm², built on TSMC 28 nm process
Advanced GCN 1D architecture
2048 1D processing cores
128 TMUs, 48 ROPs
384-bit wide GDDR5 memory interface, memory clock slightly below 1 GHz, target bandwidth of 240~264 GB/s
If AMD can produce this, then they'd have a clear winner on their hands. It should be capable of running Battlefield 3 with all of the bells, whistles and fairies on at 1080p (or 2560x1600) at 60fps constant. Something in a single-GPU product category that can do that, would be a hit for AMD, in their time of need.