A horror theme might not be bad, but they would have to water-down The Walking Dead to be all-ages. Same with Game of Thrones. I could see them picking up a TV license, just not sure what that would be.
That said, I feel like Stern needs to concentrate on making a game that has more toys and more features than the current offering has. I don't want them to try to outdo Jersey Jack, but I think that they could make a game isn't so one-dimensional and "cookie-cutter" like some of their games are. Make a wide-body, or something that has a new ruleset and playfield layout instead of the 3 pop-bumper, 2 ramp, ONE toy games that they usually put out.