Also, just to beat everyone to the punch, yes Calvin Johnson will most likely regress next year. He scored 16 TDs last year, which is a 33% increase on his previous best. The Lions had no running game to speak of, so Johnson took more of a burden in the red zone than before. Pettigrew was banged up here-and-there. Titus Young was extremely raw and will come along next year.
It was a great year but it was the perfect storm. Will he continue to be good? I certainly expect him to. Will he regress and will idiots give credit to some curse? Sure. But really it's just being sensible. Guys get the Madden cover after having an extraordinary year. Johnson had that last year. It's unlikely that it will be repeated, for a lot of reasons.
But if you want to trade me Megatron, then I totally believe in the curse. Let's make a deal.