DiMichele seems like a good crooter so having him as a full-time assistant will be a positive from that aspect.
That being said, promoting him instead of getting a QB coach from outside of the program signals that our epic sattfense will see very, very minor changes (if any). I had assumed that DiMichele was already working with the QBs, so I don't think we can reasonably expect the quality of QB play to improve much.