What to Expect (and wear)
It's called News Foo Camp for good reason. It's much more casual, informal, and spontaneous than a typical conference. While there will be an amazing array of sessions to choose from every hour, it's perfectly acceptable (and not at all unusual) for Campers to spend time in conversation rather than attend an organized session.
News Foo is a gathering of peers, though everyone's an expert in their particular field. We encourage you to bring your prodigious curiosity to the event, and predict that you'll learn as much as you share.
Sessions are usually very interactive and conversational. For tips on leading a News Foo session, read Scott Berkun's excellent piece, How to run a great unconference session.
News Foo begins Friday at 5pm, and continues pretty much non-stop until 1pm Sunday. Try to arrive well-rested, as it's likely you'll get less sleep than usual.
As for what to wear–-it's the weekend, so go with whatever's comfortable.