Well, judging by pokemon's past, i'd have to say it's a new type.
Generation 1 started it, so...
Generation 2 added colors, breeding, shinies, time, and friendship (2 new types added)
Generation 3 added... well... not much (0 new types)
Generation 4 added interchangeable forms (0 new types)
Generation 5 added interactive CG dungeons (0 new types added)
my guess is that new types are ONLY added when there's a game-changing.. well, change that revolutionizes all of the gameplay, instead of just certain minute parts (evolution, contest, computer connection) since they're not mandatory or always noticed.
as for those who are guessing it's evolution method already, im guessing it's going to be a new method. the Johto evolutions introduced friendship and time evolutions. Sinnoh's introduced location exclusive evolutions. I'm sure that Hoenn would have probably introduced version exclusive or contest related evolutions. Who knows? If they suddenly don't introduce a new evolution method for once, they might just go with trading with items, or trading to the other version.