I don't think it's been much of a hold up, anyway. Regardless of the standard contracts for rookies and the guarantee of remaining with the big club, it's still a question of him weighing the pros and cons of all of it as he's said all along. There may be practical issues involved as well. At any rate, going back to school is the only leverage he has. Not sure if that means anything much given the standardized structure of rookie deals, but there may be other things he wants/doesn't want in writing.
Anyway, it's the biggest decision of his life so far. Perfectly understandable.
GO SABRES!!!