The most interesting thing about the current mini is that I have no idea where Johns is going with this! My best guess, extrapolating not from the story but from what I perceive as the human nature of DC management, is that Barry will end up as the new Flash. I say this simply because the whole thing seems pointless otherwise, and also because Hal Jordan returning as Green Lantern under Johns's scripting was very successful and I would expect DC management to be hoping for a repeat performance. The biggest question in my mind is what will be Wally's future role?
I think thinking of "The Flash" is too small, and that we'll see multiples. That said, if they went to all this trouble and are leaving Barry retired, I'd be really disappointed.