A while back we reported about how ATI was working on a new chip called RV670. This is still very much true, but the report said that it was a mid-end chip, it's not. RV670 is a die-shrink of the R600 with some redistributed resources; a better proportion between shader processors and TMUs and ROPs. Basically this means less shader processors in favor of more TMUs and ROPs, which should seriously improve the gaming performance of the Radeon HD 29XX (the XXs are since we're not sure what it will be called).
http://www.nordichardware.com/news,6654.html