Yeah, the draft talent drop off doesn't make much sense. I'd love them to overhaul the amateur scouting.
It sounds like they did a little bit:
Improved pitcher creation & development. OOTP 13 creates fewer pure relievers for the draft. More pitchers are generated with the potential to become starters. Not all pitchers will capitalize on their potential, though; failure to develop an off-speed pitch or build stamina may necessitate a move to the pen.
I'm most excited for the overhauled AI... I hope it improves trade logic.