I had applied through my school's co-op webpage. I was asked to meet for an interview. The interview was between 30 and 45 minutes. There were two people who interviewed me, but there was supposed to be 5 (my time slot was first thing in the morning so they all hadn't arrived yet). The asked me a few technical questions like pointers in C, an algorithmic question like 'How do you calculate the angle between an hour hand and the minute hand on a clock'. They were more interested in my thinking processes then the answers I provided, and they kept asking me about myself, like technical skills and so-on. I find it hard to talk about myself so I found it hard to keep the conversation going.
I know other students found the interview panel asked hard questions (Sorry, I don't have any example), and sometimes found them to be rather harsh with some of their comments.
Even if you walk out of the interview feeling that it went hopelessly bad, don't think that's it because you never know with this group of people.
They said I would have a decision by the end of the day, and i got an offer a week later.