By end, I mean some kind of closure, since all the Megaman series are supposed to be an ongoing battle as opposed to isolated events like say, Zelda, Mario, or Final Fantasy. My thoughts:
Original Megaman - Most likely never. I think Capcom probably forgot about this or at the very least don't have any idea how the events leading to the X series is supposed to happen.
X - Unlikely. It is awful hard to explain how things go into the Z series considering the two series aren't consistent. It is possible Capcom pulls off a miracle and explain Zero's disappearance, the Elf Wars, and the birth of Neo Arcadia perfectly, but I doubt it.
Legends - Unlikely. I think Capcom forgot about this series even though they say they did not.
Zero - 50/50. As it stands Z4 could be an ending, but on the other hand they still haven't explained the Elf Wars.
Original Megaman - Most likely never. I think Capcom probably forgot about this or at the very least don't have any idea how the events leading to the X series is supposed to happen.
X - Unlikely. It is awful hard to explain how things go into the Z series considering the two series aren't consistent. It is possible Capcom pulls off a miracle and explain Zero's disappearance, the Elf Wars, and the birth of Neo Arcadia perfectly, but I doubt it.
Legends - Unlikely. I think Capcom forgot about this series even though they say they did not.
Zero - 50/50. As it stands Z4 could be an ending, but on the other hand they still haven't explained the Elf Wars.