No hard data EastWest, just some gossip on the PAforum based on some educated guesses (Randy Danielsen is the first PA promoted to Dean of a medical school, etc.) I'm sure it hasn't escaped you that I'm willing to go the traditional route to be a physician.
Now, as far as cost, I agree it is too expensive to tie people into CHCs. However, in my mind, a student would be much more likely to secure a job with loan payback if s/he had demonstrated commitment to underserved by training in such a position. I thought this might be the case when I did 3 months of family practice/peds in an IHS-affiliated (but tribally owned) clinic in Oregon as a PA student. I think it might still be the case if the clinic hadn't had such a strong preference for NPs over PAs.
Still, it's an interesting concept. I wouldn't sign a contract to say I would work in a CHC after graduation without some guarantee of scholarship/loan repayment though--med school is far too expensive to limit one's options in that way. Med school after PA school is even more expensive