Thanks for the input, guys.
I'm glad that you explained to me that the simple "hi, what's up?" approach is probably best, because I don't think I would have gone that way if I was relying on my own instincts. My nature is to try to "talk things out" with people any time there's a conflict, try to explain all my reasons for what I did, reassure the person that things are different now, etc. but I know sometimes that can backfire by overcomplicating things.
As for the issue of why I want to get back in touch, and if I secretly want him back, I really don't think it's about wanting to have a new romance with him. On a romantic level, I don't think I could forgive the fact that he chose someone else over me (but obviously, as friends, I don't expect him to put me as #1 in his life). I know he's still with the other girl and I don't feel jealous about it anymore. I stayed away from him for so long *because* I had feelings for him still and knew it would hurt to hear anything more about his relationship with the other girl. Now, though, I do think I could be happy for him being with someone else.
With that being said though...there's a part of me that wonders if maybe it's easy for him to not care about our friendship now while he is probably all wrapped up in this other girl, so maybe I should gamble that they'll eventually break up, and then approach him at that point? I don't know if that would be a good idea or not, since a reunion seems increasingly unlikely as more time goes by, plus if I showed up right after they broke up he'd probably assume I was trying for a romance again.
For me, romances have always been based on friendship first, so I really would love to have that friendship back even though the romance didn't work out.
I once managed to reunite with a prior ex purely as friends after not talking for six months. With that prior ex, it was again a case where he was the one who dumped me and then cut me off. I sent him an instant messenger message on a whim one night, not expecting a reply, but that opened up the lines fo communication again. Now things are better than ever between us as just plain old friends with no hint of romantic intent (in fact, I've even had some conversations with that prior ex's current fiancee, who seems much better for him than I was).
Unfortunately, it took me a lot longer to get over this latest guy, so now after a whole year, it seems like the odds of such a happy reunion are less.
I am the type to have a few close friends that I get very attached to rather than a big group of people, so it's hard for me to lose one of them. I'd love to have our friendship back somehow even though it wasn't meant to be a romance.