I really like a lot of the ideas in this thread. "Evil" MAA sounds just wicked! I can totally see him being there trying to fix things, good intentions and all.
Could we have it the other way around as well? A few evil warriors teaming up with the rebelling masters? I always thought that Mer-Man seemed a bit too good to be with Skeletor.
When He-Man comes back, after battling Evil MAA for a while, I can totally see them once again becoming friends. Specially if a universal crisis occurs. Like for instance Hordak and Skeletor teaming up again to conquer Eternia and stealing the secrets of Grayskull.
Anyway, I think it's too late for our ideas, no matter how brilliant they may seem. Mattel has already written Optikk's bio, and therefore mapped out the incorporation of NA into the regular MOTU-universe (yes, that's Masters of the Universe-universe).