McDaniels has turned out to be a pretty good coach. the addition of Mike Nolan as the DC and the complete domination of Elvis Dummerival at OLB has gotten the broncos rolling
I don't believe Orton was a bad QB to start with, or that McDaniels "turned him into something" else either. Different QBs have different strengths and weaknesses and the key is putting them in position to play to the strengths without leaving the weaknesses exposed. Some coaches understand how to figure that out and others try to fit the square through the round hole.
Going from a team with a bad offensive line and no recievers to a team with one of the best lines in football and Brandon Marshall probably had something to do with it too.