Isn't there a tile based shading technique that manages to decrease its "expensiveness" both in bandwidth and shading? Maybe im confusing it with something else. Wasn't it mentioned on the recent frostbite 2 presentations and cryengine 2 as well?
Yeah, tile-based deferred. Andrew covers it here. Looks very promising and he compares it to existing deferred methods.
http://visual-computing.intel-research.net/art/publications/deferred_rendering/
IIRC, Bizarre Creations did something similar (if not the same idea) for Blur on PS3's SPUs.
http://www.slideshare.net/nonchaotic/a-bizarre-way-to-do-realtime-lighting