At least, io9 (beware, link contains massive Heroes and Transformers spoilers, among others) says this is a Y-Wing, and since this week’s webcomic deals with them I see no reason to doubt. It actually looks kind of like a cylon raider – something about the bit in the middle – but that’s why I’m not a spaceship guru. (Still, we did see concept art of this one way back.) And is that what I think it is in the background? Bypass the actual spoilers to view a larger version.
…Or just bypass them alltogether with the StarWars.com preview, and another still.