The thing that annoys me most about FB is its built to keep people engaged and spend too much time on it. Its interface and updates are kinda built around being "addicted". Why can't they provide it in simpler way, to keep people connected and let them do the things which matter more.
What if google built the FB? (oh yeah, they tried that with Orkut, but I guess it lost the game because of interface). Mark Zuckerberg talk about social graph all the time, but I don't think anyone on facebook have a true graph.
People will project themselves the way they want to on FB. Funny, Clever, Kind whatever they want to. Its more of a marketing tool for me. Kinda personal branding tool.