Very professional communications--had very little personal interaction until the interviews.
First an onsite interview at my university (because I'm nearby Microsoft campus). That was about a hour, very open-ended. He asked me to design a product (a TV, computer, software, or something like that).
Second an onsite interview at Microsoft campus. There were four interviews in total. No interviewer had a list of questions, but each definitely had a particular thing he wanted to discuss. The first interviewer asked how I (a) take input from users, (b) filter down user inputs to actionable items, and (c) communicate my decisions back to users. He always asked, "how would you do it better?" The second interviewer was more personal--she asked why I wanted to work at Microsoft, why I wanted to be on that particular team, why program management, and the like. She asked how I would handle a particular situation that involved managing limited resources and time. The third interviewer asked very direct questions, such as "You want to write a card-shuffling algorithm which recreates reality (not randomness) as closely as possible. Walk me through your thought process." Fourth interviewer was the boss--he just wanted to say hello and see if I was a friendly person.
Overall, they wanted big-picture, end-to-end thinking. They were all about the process of making decisions.
Two of my interviewers were friendly. One was apathetic, and the other was downright cold. There was no feedback during the interview, either positive or negative. No one ever joked or smiled.