I was interviewed by a panel of four. The interview took about 40 minutes. Dress was casual. I think all four of my interviewers were wearing shorts (it was a Friday). I would definitely dress up, but you may not want to wear a suit.

Interview took about an hour. Started with an opening about who you are and background topics. Asked about my current job and it's responsibilities to understand my current skill set. Gave a description of what I'd be doing there and asked what type of work environment I thrive in (static or dynamic). It was pretty laid back and felt more conversational, which took away much of my nervousness.