The thing is, this kid enjoys a challenge. You can tell by the way he talks, and heck his myspace even notes it. So you can take that one of two ways.
1) He wanted the challenge of working to achieve a USC offer, and now that he has achieved that, he is intrigued at the idea of battling 2-3 really good QBs at the school that breeds them and eventually leading USC on the field as a starter.
2) He already achieved the only goal involving USC which was to get an offer, but the real challenge he wants to take on is building UT back up to the way it used to be. He wants people to think of him when they reminisce about how UT came up and became the team it once was.
Those are both excellent challenges and I guess we'll just have to wait it out to see which one means more to ole JS.