That's a pretty massive 'if'. So long as 'fans' of the X-men continue to support the the films, there will be no happy ending. Fox will have no reason to relent on thier claim. The success of these films is litterally choking the life out of these characters.
If this continues long enough, I'd imagine that Disney/Marvel's interest in the X-men characters will completely evaporate, save for stalwarts like Wolverine.
Regardless of Disney and Fox' little feud, after a few years it won't matter at any rate. The span of attention for comics fans seems pretty limited in it's scope. Now that the Inhumans have cemented a large role in the Marvel Universe, in a few years most people discussing them in forums like this (and most definately the 'tumblr' contingent) will assume it was always so and there will be no looking back.
I'm pretty sure the Inhuamns are here to stay.