C-SPAN has a general discussion going on, more or less, "what should Bush's role be once he leaves office?" or "How can Bush help Obama?"
For a start, in any situation, all Obama has to do is ask aWol "What would you do?" and then do the exact opposite. Things would be far more likely to come out okay than they ever did under the current regime. That strikes me as being such a no-brainer that I'm surprised C-SPAN is wasting air time on the question.
As for the more general question of what should Bush's role be once he leaves office? Nothing. He needs to get settled into his new digs in Texas and disappear quietly from the public stage. I don't even want to suggest he emulate Jimmy Carter and get into building houses for Habitat for Humanity -- any structure that aWol touched wouldn't stand for very long.