Most of the problems I solve don't call for OO, but it's definitely useful. The one bug I can think of that I would have avoided by using OO was the one that I introduced just before asking news.yc to evaluate ourdoings.com last time.

I think pg is right not to rush to implement an object system in arc. There are many opinions about what the right object system looks like. Anybody without an opinion should stay out of the way. Someone else can implement an object system for arc later.