Ultimately went for Engineer because it is just looking very funky. Love the mechanical theme. Love the gadgets, kits and the flame-thrower. Turrets are win.
Well I wanted to be melee, so Thief still appeals. Warrior would have been first choice, but I'm set against playing 'very popular' professions. Warrior and Guardian are looking consistently popular in all sorts of polls.
For a ranged character it is a bit of a toss up between Ranger and Engineer. Well, I loved Mesmer in the first game, but this new Mesmer seems too... different. Subject to change, of course. As someone said earlier, a huge number of voters still aren't sure yet, given that information is still in major flux.
If you haven't, go contribute on http://www.gw2census.com - with over 5,000 voters it is not only the most populated GW2 poll so far but it contains more information than just professions - so you can filter all sorts of combinations of data such as "how many Charr are played by roleplayers?" or "Which profession appeals the most to predominantly-FPS players?"
@Bloodhunter I always smile when I see your avatar. Someone with such a gory name has such a cuuuuuute avatar!