The only thing they really could do now is put nothing bigger than a restaurant in that space. It is kind of cornered by the haunted mansion and It's a small world ride building. Unless the ride had one looooong corridor that allowed it to get out of the narrow place in between the two buildings, you won't see another dark ride, etc. there anytime soon. The building itself is really a nice addition to Fantasyland, it fits in very well for that side... and it will still fit in if we get a rumored renovation to look more like Disneyland's Fantasyland.
I think the view of the Contemporary that we are supposed to have will be nice... but only for a while. I hope we might see an attraction back there... maybe focus on the original concept for tomorrowland instead of trying to mix disney characters with a bit of Jules Verne... It doesn't seem to be all it could be.