It's been a total team effort inspired by Tebow.
Did you forget that this was the same defense that couldn't hold up with Orton throwing INT's on short fields? Since Tebow started, the run offense went from #28 in the league to #2. Think about that? 5 initial games where they had no running game to now where their 2nd in the league that quick. That's the big story of the turnaround.
Running the rock cures all problems. Denver's defense isn't no longer gassed and the opposing teams only gets a few possession each game.