GamingUnion has an interview with Capcom's Seth Killian up for reading, talking a little about the likelihood of a new Mega Man Legends among other things. His words make me very hopeful:
GU: Is Capcom planning anything new with the Mega Man Legends series such as a 3rd installment or us getting the PSP ports of the 1st two games from Japan?
Seth: After Marvel vs Capcom 2, MM Legends is probably one of our most fan-requested games. MM creator Keiji Inafune is certainly aware of the fans' request—his office is basically a shrine to the stuff he’s gotten from fans over the years. There are no plans right now, but Mega Man 9 came totally out of left-field, so you never know with that guy. If he gets inspired, and things can happen very quickly.