Just search on "dev manager" and agile. You'll come across lots of articles from scrum proponents that attempt to severely downplay the need and role of dev managers and sometimes claim they aren't needed at all in an agile shop.
The one thing they usually don't mention is all the new agile servant leader positions your company will have to hire instead of dev managers.
The one thing they usually don't mention is all the new agile servant leader positions your company will have to hire instead of dev managers.