I'll be getting both X and Y.
It's hard picking a team when you don't know everything about the Pokemon yet.
For Pokemon Y I'll be using:
Fennekin - I've always started with the fire starter been my thing ever since Red/Blue. Was very disappointed with Gen V's fire starter.
Noivern - So cool looking and being a Dragon-type made it even better. Will probably be my flying-type.
Doublade - It's a spirit possessing a sword how cool is that. But No guard ability is interesting, and not being effected at all by Normal/Fighting/Poison moves is just awesome.
Malamar - Right when I saw this thing I knew I just had to be on my team. It's typing/abilities are interesting and it's biggest threat is being x4 weak to bug.
Spritzee - Simply because it's exclusive to Y and to test out the new Fairy-type.
Tyrantrum - This guy is great looking finally a T-rex Pokemon. Let's just hope he doesn't turn out like Rampardos High Atk but pretty crappy everything else. With Tyrantrum's large range of weaknesses it wouldn't be good.
Pokemon X I'll be using:
Chespin - I believe it'll turn out just like Torchic's line, first evolution is a little derpy but it's final evolution becomes Epic.
Talonflame - Will most likely be my flying-type. A fire/flying pokemon is rare being Charizard the only non-legendary to get this type. Only big down fall is x4 weakness to rock.
Cluncher - My water Pokemon no word on it's ability yet but it looks pretty sweet, having a feeling if it get's an evolution it'll be pretty awesome.
Swirlix - It makes me laugh, and it being a Fairy-type it makes me laugh even more imagining Garchomp being killed by cotton candy XD
Furfrou - I love this thing in it's original shaggy style. But it's ability is pretty good only receiving half damage from physical moves.
Aurorus - Very interesting because of it's ability. Changing normal-type moves to Ice can become very threatening to Dragon-types and others weak to it. An it's move Freeze Dry actually being x2 weak to water is pretty cool.
Of course my teams will most likely change since we haven't seen all the new Kalos Pokemon.