I feel Blake will be able to get a solid post game when he's in his prime, be a better man defender than he currently is, though not terrific, show better rebounding skills ( that doesn't nec mean getting 14 boards a night ) and show better leadership skills. As well as hitting 58-68% of his free throws yearly.
His passing game currently is very good for a big man, I think that's about where it's going to stay at the rest of his career. I can't see him adding a 3pt shot or getting terrific at shooting jumpers either. He needs to be coached correctly and be taught that big men play in and around the paint, not on the perimeter shooting 20 footers.