If he comes back next year, I would say he'll be the best player NU has had since Lue and Piatkowski. I know Venson Hamilton was Big 12 POY, but Palmer can really a team on his back and carry them.
I don't think he'll be back unfortunately. It's his 4th year, so I assume he'll finish his degree this spring. His stock won't get any higher after the run he's been on this year.