Successor of Radeon HD 7970 has (by that slide - maybe Fake, maybe not) 20 percent higher Compute Power (not gaming performance), based on EGCN (Enhanced GCN) and will be launched Q3/2012 or Q1/2013. Specification: 2304 Stream processors, 384-bit mem bus, 3GB GDDR5 6 GHz. TDP 250W, idle 3W.
Next info is about Dual monster Radeon HD 7990, the original information was, that it will be launched in Q1. From a reliable source I know that AMD still can not produce sufficient cooler for card with higher power consumption than Radeon HD 6990. The card disappeared from the roadmap for Q1 and is not in the Q2 too. It may be completely canceled, or may come out later.