As Facebook (or social networking in general) becomes more and more prevalent, it seems that it's going to eventually need more and better ways of grouping and organizing your friends. My friends list includes extended family members, an ex-CEO of a large company, kids in high school, my boss's boss, and people I've only met online. How do I make sense of all of that? You can create multiple friends lists, but those seem to only be used for controlling permissions.
Maybe it doesn't matter, at least to most people. I'm a fan of structured information. I organize all of my files and emails meticulously, and like to stay on top of things. I never really search for things on my computer; I know exactly where I filed everything. So, that I have such an unorganized friends list is bothersome to me. But I realize that most people probably don't care. Facebook is really good about letting you search for peoples' names anywhere and everywhere it's appropriate. So, you never really find yourself needing to actually look through your friends list.
I'll admit that for what kinds of features Facebook offers today, further organization capabilities are not really required. It just seems that they might be in the near future, and I hope that they have some sort of plan in mind.