I hear what you're saying... I just think he will keep it up long term. Unlike some in this thread, I don't think he's played THAT WELL. I think he has a LOT of improving to do. The thing is, I think he can and will improve. He has the desire to succeed, he's smart, he's not going to let success go to his head and he has intangibles. That combined with the fact that he has tremendous vision and running ability and I think you have a QB that is going to get better and continue to win (not every game, but in general).
Now, the Bronco's will most likely make the playoffs. And if they do, they probably will and should lose in the first round. Let's be completely, 100% honest. The Broncos, as a team, are very very poor. Look at what they have done over the last two years without Tebow. They've lost, repeatedly and horribly. They traded their only good WR. They have inexperience all over the field and their defense is AVERAGE. They defense seems better now because they play a ball control offense most of the time. But that defense was atrocious prior to Tebow taking over. To say they are a good defense now is a joke, they are average.
IF the coaching staff gets behind Tebow.. and I mean really gets behind him, if they can bring in some talent on offense and improve on defense a bit more, I think you have a legitimate team that can compete. Not because of Tebow, but with Tebow. What they have now though, they will continue to struggle to get wins, but will get more than they should BECAUSE of Tebow.