FF has had a couple of storylines where they tried to deal with the aging of the Marvel U without a formal reboot. The first I remember was an storyline where the Skrulls (those guys are like the Marvel version of the wall that Superboy prime punched) hit the team with an aging ray. When they finally got around to reversing the process, Reed explained that they had somehow reversed themselves to be even younger than they originally were.
It didn't sit that well with me at the time if, for no other reason, the fact that art didn't portray the FF as looking any different than they did before the storyline started.
