Despite many programs still struggling to take full advantage of 2 or more cores, AMD appears to be planning on jumping past 8 cores and going straight for 12! AMD has dropped more than a few clues that something like this was coming:
"The first breadcrumb comes with a new "native six-core" Shanghai derivative, currently codenamed Istanbul. This processor is clearly targeted at Intel's recently announced six-core, 45nm Dunnington processor."
The second clue was when AMD execs and engineers began to stop referring derisively to Intel’s practice of putting two chips on a single die, and began to examine using that approach themselves.
There are no early performance estimates worth reporting at this time, but we'll be certain to keep you informed if anything reliable crops up.