Since interim titles aren't real titles, Barao isn't on the list. That being said, Cruz will be the first to lose his strap, to either Barao or Mayday (hopefully Mayday). However, if Dominic doesn't fight in 2013, the next likely loser would be Mighty Mouse. There aren't any fighters at Flyweight that are clearly at the top of the heep. It pains me to say, GSP could also be the first to lose. Definitely not to Diaz, he's a joke, but to Hendricks. He's just as good a Wrestler, if not better, with devastating power. Not saying Hendricks will beat GSP, GSP has the overall better stand up and is better well rounded, but he's a legitimate threat (unlike Diaz).
Aldo won't lose anytime soon. Don't kid yourself, Frankie's not a threat. The only advantage Edgar has ever had is speed, him dropping down where everybody is as fast or faster, he's ****ed. Bendo won't lose, he has no legitimate threats in the near future. Silva won't lose anytime soon. With fighters like Sonnen being taken seriously, Bones is in no danger of losing his belt. Cain, if he can stay healthy, will dominate HW for a very long time.