Posted Dec 09 2013 - 09:37 AM
More Chima ultrabuilds would be great. They could even reuse some of the molds from previous ones in new colors for characters like Windra, LaGravis, and Crooler. However, I don't know how likely that is, especially since most of the characters from those six tribes, other than the "main characters" already featured, seem to have less significant roles next year.
More Super Heroes ultrabuilds would also offer a lot of potential for new designs, but as Lyi said, I don't know how well they sold the first time around.
Star Wars is one of those things I wish were possible. I'd love to buy a constraction set of Darth Vader, or Boba Fett, or a Stormtrooper, or C-3PO. Even characters like Chewbacca might be possible with some of the more organic-looking detail elements like the ones from the Chima constraction sets. But sadly, Hasbro still has an exclusive license to produce Star Wars action figures, which they've kept a tight grasp on since they acquired Kenner.
Out of other current themes, hard to say. Ninjago would be a real challenge since all of the Ninja costumes have had at least some textile-based component. The Lord of the Rings/The Hobbit could do that for giant/creature characters like the Balrog or the Ents, but chances are a System approach would allow for more detail and a more versatile building experience, especially with so many different kinds of joints being available in System. Ninja Turtles could work quite well, but personally I have no interest in that theme, though I don't think it's a bad theme by any stretch of the imagination. Castle could maybe be cool?
At any rate, I don't have a whole lot of ideas that I'd really like the LEGO Group to pursue. Then again, if they DO release any other constraction sets for existing themes, maybe they'll appeal to me in a way that catches me by surprise.