Well-
Almost all of the Lv.X's will be played. We have Mesperit, Uxie, Azelf, Magnezone, Ryperior, Mewtwo, and Gliscor. Then, we have Kingdra, Ninjas (shedinja/ninjask), PoliPower, Tentacruel/Lanturn, Starmie Snipe, Frosslass Spread, Luxray varients, Groundonk (or Donkey, as I like to say), and Armaldo. That is basicly what will be dumped into the Metagame from the new set, IMO.
Then, I could see some older decks returning. Electivire, for one thing, could make a comeback with all the water going around, Eeveelutoins will see more play becuase Gallade sees less, and Empoleon could get more play.
Rogue FTW!