I was actually thinking of both a reboot and recast, but a recast, in and of itself, carries the danger I was thinking about; I've bought into RDJ as Iron Man and having anyone else play him might not work for me. He would be a very, very, very tough act to follow IMO. On the other hand, Ruffalo was terrific as Banner/Hulk even following a very, very good actor (Norton). I'm not saying it can't be done, but it does carry some dangers. The bottom line is that I am totally loving this franchise and ought to just relax and enjoy the ride. Retiring the characters for awhile might work. I hadn't really thought of that.