I just remembered that there were rumors a few months back that Ubisoft was trying to acquire Square's western division. I wonder if they could be one of the interested parties here? I don't know if they could afford the whole kit and caboodle though, probably just the western division.
I actually wouldn't mind that much if Square got split down the middle, with say MS or Ubisoft getting the western division (Eidos, Crystal Dynamics studios/Tomb Raider, Deus Ex, Just Cause, Sleeping Dogs, Thief, etc. IP's) and Sony or Tencent getting the JP division. Probably an unlikely scenario though. Whoever buys it will most likely want the whole thing.