It's really about nailing the "Why Reed" essay and by doing that being completely honest about knowing who he is and what he wants to do when he gets there. I think it really helps to show that he's done his homework about the school. Is he comfortable with the idea of spending 70-80 hours a week on class and homework? How does he feel about being so far from home and in a different social culture? I think what they are most interested in are writing skills and critical thinking ability. The admissions process is a joint student/admissions staff process and so they really look for students who they think are a good social fit for the school and can handle the academics.
I was admitted in 2004 and I think it's a somewhat different school from when I applied. Test scores and GPA are up on average and the drop-out rate is down. Reed is going places and doing it fast, it's just not quite clear in what direction. I'd also take a long hard look at the financial aspects of course. The cost of attendance went up every year I was there and I don't anticipate it going down. A Reed education is expensive, and when compared to other options it might be worth it (I didn't get any financial aid from the University of California System, I did from Reed), the key thing is a desire to drown in intellectual life and a stick-with-it-ness, otherwise it can be overwhelming.
The good news about the change that the college has taken over the last decade (and now with this coronation) is that as a parent, you can rest more assured that the decadence that characterized the college for much of it's history is on the decline. I am a 2009 graduate with a B.A. in History, feel free to send a P.M. if either you or son have any specific questions about Reed academics and student life. I don't regret going to Reed, but I do have some strong opinions about how it's run, however, I still think it's far ahead of most other institutions in basic things such as classroom environment and academic rigor.