I think the result is probably a larger number of shallower friendships than you'd have otherwise, or at least that's the pattern I've noticed, and I don't think that's necessarily better. The rest of most people's time on there is generally spent idly browsing the trivia of other peoples' lives. I just don't think it's a very effective use of users' or engineers' time.

I used to use FB a lot, especially in college, but aside from being great for organizing parties, I've found that I like the old ways a lot better. For actually communicating and having conversations with people, IM and email are actually more robust/effective/universal, and aren't engineered and A/B tested to hell to suck up attention as effectively as possible.