Pros
Professional development skills Networking opportunities Meet like-minded people your age Looks good on a resume Education award Learning to work with all types of people (personality-wise, but also cultural differences)
Cons
Education award is severely limited. Not only is it taxable, it is only applicable to federal loans in good standing. Also, if you work for a second year, you may no longer be eligible for loan deferment and since you won't get the ed award until the end of your term, it's pretty useless. It is also not applicable to any bills you may have acquired from courses taken prior to your year of service (i.e. if you serve from 08-09, you can't make payments toward classes from Summer 2008 or any time earlier than that).