dont forget new reno in fallout 2!!!
the guy has proven himself time and again and hes a kick ass designer. id like him to work on somethign which allows him to have a lot of creativity, and not work on dnd where his creativity would be limited a lot.
Given how original Planescape Torment was, I doubt a future D&D game would be that inhibiting for CA and crew. Plus, they could set the game in Eberron, which would free the designers from the constraints of more established settings (aka baggage) of the Forgotten Realms and the like.