I could see them getting the Lord of the rings license, which would honestly be pretty sad since they would not really do it justice. But I could see Todd grabbing that, especially with the upcoming movie and game(s) that are in the works. A full line of LotR would be cool, even if the individual figures weren't great. It is a pretty big IP, especially since we haven't had many figures of these characters (let alone good figures of them) since maybe Toybiz, Inart and third parties notwithstanding.
Apart from that, well they could do Disney, sure, but I'm not sure if Mattel still has the license. They could do Fromsoft games, Ghostbusters, do a movie maniacs line of articulated figures from many movies (I could see that one working). A few anime licenses could be cool as well.
But I don't see any of these working, with those higher prices they're doing now, without significantly improving the figures and their designs. A new, modern articulation system should be in order, and a focus on great, proportional sculpts and poseability.