According to Charlie, the roadmap for the 6000 series cards has been brought forward and we could be seeing a launch of the new cards as early as this autumn, rather than at the end of the year/start of 2011 as initially thought.
In short, as the road map to get to 28nm has slipped/looking uncertain now, the idea is to take the uncore elements of the Northern Islands GPU that are planned for the 28nm process and combine them with the Evergreen shaders and put it on the existing 40nm proces. This hybrid is to be dubbed the Southern Islands GPUs.
Anyway, you can read the article here:
http://www.semiaccurate.com/2010/03/...eration-outed/
Once upon a time I disregarded most of the stuff Charlie wrote, but after getting most of his predictions right about Fermi, I take his writing with slightly fewer pinches of salt.
Probably won't allow a mega jump in performance if it is still on 40nm, but it might be enough to take back the fastest single GPU crown.