This is one of those irritating topics. Take Square Enix of the List of potential buyouts. Never going to happen.
Major Japanese developers WILL NOT BE BOUGHT.
SQUARE ENIX
CAPCOM
SEGA
KONAMI
NAMCO BANDAI
Take these companies off your list. These companies would more than likely merge with one another or an outside gaming entity, than be bought by SON/NIN/MS.