I'm hoping for a Romance Based Gamepack Next. This is one theme the developers seem to be overlooking. Romance in TS4 really needs to be vamped up. Family was lacking for a while and now it's almost perfect except for Generations Gameplay stuff missing so it's time to vamp up Romance.
If not romance then I'd love to see a Themepark Gamepack next. We had carnival rides,games,etc from the TS3 Store now it's time for TS4 to step up to the plate but I want a pack dedicated to Theme and Waterparks and a new Lot Type Amusement Park. I want our sims to be able to ride roller coasters,ferris wheels,carousels and gondelas and maybe visit a marine aquarium and or zoo while their at the fair.