Personally, I am divided between human and sylvari, but sylvari is more likely.
Asura! Midget with explosives, whats not to love?
I took the cheap route of "I don't know" as the Engineer is the profession I am the least excited about. I just don't like the tech stuff.
I like the idea of an engineer class, but the previews of it I've seen look really goofy. I think a large part of it has to do with me not liking Charr wearing human style clothes. Charr look badass in the GW1 clothing; they look downright silly in a wizard's robe.
That said, if I am able to make a Charr that doesn't wear pants, my engineer will be Charr.
I think you're likely to be able to do that, Fluff. The Sylvari get to wear leaves, I can imagine charr being able to wear charr-specific armor. Or at least, that there would be enough variety in armor art that you'd find something that works for you.
The profession appealed to me more on release than it does now, but I'm still planning on making an engineer. Mainly because the idea of a human engineer appealed to me. I thought of all those poor saps we helped over the Shiverpeaks in GW, who mostly got slaughtered by centaurs, and the Krytan villagers who had no real means to defend themselves effectively against the undead. They were pitiably impotent in a world where even plants were magic-powered people killers.
I like the idea of average, common GW people finding a way to fight back, even if they haven't been blessed with the gift of god-given powers.
I'm generally not interested in giving my GW characters histories, back-stories or whatever. If the profession doesn't play well none of this will save my engineer from deletion.