I'm voting "no penalty".
Keith Collantine is right when he says that we can't have penalties for every driver who loses control by accident and happens to hit someone else. Yes, Vettel has done it more than once. Yes, he's an arrogant little ballbag and it's about time he was taken down a peg or six. But the last time I checked, drive-thru penalties aren't handed out to people just for being arrogant ballbags. They're handed out for breaches of the regulations, and I'm not sure that crash really counts.
It is, however, time someone sat Vettel down and asked him what the **** he thinks he's up to.
Other crashes aren't the same though.
1) they where not wheel to wheel in a corner
2) it wasn't wet and just misjudged a braking point
3) he lost it due to an aggressive shift in direction, which was avoidable.
4) he took out a championship contender whilst keeping himself in a decent point situation.
I'm sure all that and more meant he got a penalty while others haven't. As JB it was an odd accident, it wasn't just a clipped wing while side by side, or having no braking power in the wet.
However after saying all that it's a very close call and I voted no opinion.