In my book, if you win the championship, you are a worthy champion. With Vettel, I'm not sure how there can be any doubt. Like Alonso, he seems to win if the car is capable of it. The Red Bull must have been quite a pile (relatively speaking of course) earlier this season.
As for Hamilton and Mercedes, I remain depressed. However, at least he won't get his hopes up there. At McLaren, they give him almost enough car to win, but not quite.