Oooh. This looks like a fun thread. Okay lets see...
FF7 exclusive remake for PS3
A Square Enix exclusive MMO game,
Gears of War Series comes to PS3
A Bungie exclusive game for PS3
Blizzard exclusive game or WoW spinoff
GTA exclusive spinoff game for PS3
Spore comes to PS3 after Wii but before X360
A major online media (like Google) supported infrastructure to rival Microsoft XBL
That is the best I could come up with, outside just going plain stupid. Any TWO of those would negate most of the loss of exclusivity of FF13