I like him. He's built to run. Like others said, spend a LOT of time on your flat work. With OTTB's I do a lot of circles, with reins encouraging the horse to stretch down. Also work on transitions and half halts. Keep in mind, this horse has been taught to pull against a riders hands... not yeild to them. DO NOT get in a tugging battle, you will lose, or at least kill your hands in the process. Allow him to move out a bit. The biggest mistake I've seen with OTTBs is that people try to make them move like smaller horses. Do not try to package the trot, allow it to stretch instead of march (which he'll be prone to with a shorter back).
When you do move to jumping, I'd spend some initial time on grids. His current natural form is knees down bunny hop. This makes sense with the slope of his shoulder and length of legs. You need to teach him to jump in stride, bringing his knees up and rounding his back. It will make for a smoother, more economical jump.
I think he's cute, and has a nice soft eye. I don't know how far he'll go (most of that's heart, not talent), but with the right personality I'm sure he can do anything.