Without a doubt W&M's program is better than UNC's. On the men's side, I think UNC pretty much concentrates all their effort on basketball recruiting. William & Mary has been a regional powerhouse for the past few years now in cross, plus it's a great place to train. Virginia has come a long long way the past three or four years and are turning into a perennial contender for a bid to D1 nats. It's not a bad place to train, but personally I preferred Williamsburg--more scenery and less traffic. W&M is also known for turning 9:30-10:00 guys into solid college runners, so if you get that 3200 time down a little next year you may be able to get a look. But the atmosphere is rather competitive, and even if you "make" the team freshman year you'll probably have to keep up progress to stay on due to roster limits.
I don't know how active they are right now, but a couple years ago William & Mary had a number of guys who weren't even on the varsity team (at the time) running 2:30-2:40 marathons, so there would be a good running group even if you aren't on the team.
Another option, especially if you run fast this year but don't get the SAT scores or grades you need to get into UVA, W&M, or UNC, is to go to State. I know it's got a bit of a redneck reputation, especially among Duke and UNC students, but there are plenty of smart kids there and it is a very nice area. The outdoor track was getting a total makeover this past year, but the distance squad, along with W&M, is tops in the region.
And by the way, I don't really think W&M or UVA are better academically than UNC, I just get a little ticked when people tout their own school as "the best" all the time. It is more a question of individual fit; I don't mean to stir up anything.
On the other hand, there are a number of good smaller schools in the region. Academically, the best ones are probably W&L, Davidson (I was rejected there, alas), and Mary Washington. I don't know much about the running environment at Davidson, but a lot of people who have times like yourself end up going D3 and having a good experience.
Another one to keep in mind is VCU, their distance squad is definitely on the upswing.