I don't know, I think it can work.

Two examples from my personal life.....

1) I asked this guy out in college that I had met a few times. We had a couple of classes together, so I struck up a conversation and asked him out. I was shot down but we still hung out, and he ended up becoming one of my best friends in college. I got over my attraction to him and we had an awesome, completely platonic relationship. Unfortunately we lost touch after he graduated.

2) The person I'd call my best friend now is one of my ex-boyfriends. We dated for 8 months, and it didn't work out... but suprisingly, we got along much better after we stopped dating. We hang out, can talk much more freely, joke around about our dating lives, and he's even going to be standing up in my wedding next year

So I think it really can work!