That's because you are asking us to vote based on gut instinct, and in most cases, we are just going to vote our favourite driver!
If Redbull have an awesome car again, then yes, Vettel will most likely win it again, Webber blew it last year, Vettel is clearly the quicker guy... especially in Quali! If Ferrari get their act together, then Alonso is in with a chance, as I think Massa is history, he's living on borrowed time, he will have to yield to Alonso if he's ahead no doubt, with team orders coming back in. If McLaren has a good car from the outset, then I would expect Hamilton to be beating Jenson in the same car.
Too many factors, and as we know little about the new cars performance, we can't really vote honestly on who's going to 'WIN' the driver's championship.