Michigan State too....and the first year they're doing them too. So no history to go off of!
I actually bought the ethics book to prepare without reading this thread first haha. Basically I'm torn between winging it and trying to practice. I know I'm going to freeze up a bit either way, to be honest. Most schools seem to provide you with a small notepad to jot down your thoughts, so that should help.
I've heard from friends (who went to different schools) that some people had 4-5 minutes of awkward silence after they spit out their answer (you can't leave until your last minute is up), while others were cut off after they ran out of time. One of those friends told me that whenever he stumbled, the panel would ask him a question to help prod him back on track (I'm assuming they had a feeling he was going to nail the question, but just got nervous). Other schools do not allow the panel to talk to you (besides a hello, I assume) to preserve consistency between interviewees.
To me, this style is severely intimidating. I can handle myself quite well in most situations I might find myself in during my career, but something about MMI's makes me wanna hurl. I think it's the formality of it. Not to say that a traditional interview isn't formal. But I'm picturing hearing doors open and close ever 8 minutes on the dot, dead silence everywhere else. I'm really hoping Michigan goes out of their way to make this relaxed. I've read that some schools are extra friendly when they hold MMI's because they are typically more stressful.