So i managed to dig up very, very few specs on the new AMD GPUs, even after watching the entire live broadcast of their launch party in Hawaii.
First, the 7970 equivalent of the new series will be called the R9 290X. As far as crunching goes, TFLOPS rating is ~25% higher than the 7970 (~5 TFLOPS vs. ~4 TFLOPS). Also seems to have 4GB VRAM.
These can be preordered beginning Oct. 3rd. Price unknown, but guessing $600 - $650.
Overall, the higher end GPUs will be known as the R9 200 series. Lower end will be the R7 200 series, and even lower R5 200 series, both which appear to be rebrands of the 7000 series.
No more Xfire connections on the top of the card. GPUs will now communicate through the PCIe 3.0 bus. What if you don't have 3.0? No idea. Xfire is overrated anyway :p
Offloads audio to be processed by the GPU. No more sound cards needed or CPU clocks used up.
Stated to be more power efficient, though TDP is unknown.
Edit: 300W TDP mentioned. Not official though, but likely. Also 6GB versions of the R9 290X are expected later.