Well doesn't it all depend on how you feel about him? I'm on a year abroad too, and I'm in a long distance relationship. We would never have considered breaking up over this reason (we'd been together just over a year before I went on my year abroad) as we were and still are really, really into each other. Although it is difficult at times, it's definitely worth it, in my situation. Now with yours, you need to think about whether you want a relationship with him or not, not just think about the fact that you (might) miss him. It's only natural to miss people and home, but it doesnt mean to say that you have to enjoy your year abroad any less. You can still go out and have fun with your friends. Sure, I think that, to be completely honest, I would be happier being back at uni nearer to my boyfriend and living with my best friends, but it's not a reason to give up on my year abroad, or make myself feel miserable, or purposefully have less fun.
Whether a long distance relationship is worth it or not, totally depends on the relationship. Do you really WANT to get back together with him? Is the relationship worth it? Did you have a good relationship before? Do you think he really will be committed to a long distance relationship?
When are you on your year abroad until? I've got til June. Maybe if you're unsure, it might be worth staying friends for now and then see how it goes when you get back? I think at this point, you're going to miss him either way - whether you get back together or not. It's likely that you'll miss him even more if you get back together, and that it will change the daily routine of your 'new life'. Mind you saying that, just because you get back together, doesnt mean that you have to talk every day and be in constant contact, and therefore might only be a minute change in your life.
Hm..well I dont think that helped you much, sorry. Ended up a bit confusing!
If you want to, feel free to PM me since we're sort of in a similar situation (of being abroad and missing people!)