Jose Aldo managed to hold on to his title at UFC 156 by taking an unanimous decision over Frankie Edgar. It was close, but Aldo managed to inflict enough damage to sway the judges in his favor.
Now Aldo will look to the future in which a new set of title challengers will emerge. The Brazilian has been on the shelf for quite some time prior to UFC 156, which has given opportunity to a number of guys to step up and warrant a title shot.
Edgar could make a claim for a quick rematch, but that would mean jumping ahead of the guys on this list and a surging lightweight as well.
I'm not ready to call any of these fighters as being the guy to take out Aldo, but they certainly have earned a title shot and could provide an interesting matchup for Aldo.