I think the fact that they had that Fez intro into COBL at Cape Town gives us a hint that they may be open to trying out the song live. Maybe at one of the south american/mexico city shows they will open with it?
I think the way pepokiss described it would be awesom, although I don't really care if they play Soon before it. I think just starting out with the house lights going down, some awesome new visuals on the screen as Fez begins, and then the band goes on stage and when Being Born begins - with that big guitar, bass, and drum EXPLOSION part at the beginning - the lights flash on and Bono can be on the elliptical walkway dancing and singing and screwing around like he did with Stingray Guitar.
I really liked the idea of continuing the "let me in the sound" loop so that they can segue into GOYB. That would be really cool.