As I stated already, HALO!!!! It maybe a little violent for kids, yes, but it would attract a larger adult audience, giving LEGO more money to make what we want. I say that because adults have more money than kids do and it would sell more. If this were to become a theme, it should be done as Microsoft did. Start with Halo: Combat Evolved, and work their way up. The first set should be called Revielle. It would contain Master Chief, 2 Marine Crewman, and 2 Brick-built elites, something like Saber-Scorpion's, and a small portion of the Cryo Bay and the control room up top. Maybe the whole Cryo Bay room in agood 70-80 set. LEGO could also do minifig packs, like they can't do for star wars. The Vehicals would be awsome, and maybe weed get more purple ish colored bricks with the covenant sets. Just something to think about. What does every one else think of a HALO them? Since it's a liscensed product, we would get fleshie Marines.
Other ideas would be like a modern or futureistic military line. Have the Navy, Marines, Army, Air Force and ,Coast Gaurd and maybe have that a branch of theme of the city line, and preferably with fleshie heads.