If you are going to get an ipad, I'd get a keyboard case to go with it. Logitech/belkin make them for both ipad and ipad mini.
I see a couple of people using this combination in class, it seems to be getting more popular. Although at the moment at least in my classes macbook air's/13" macbook pros are probably the most popular - and pen and paper is pretty much non-existent (say 1 or 2 people in a class of 60)
at least in law at my uni.
But it really depends on your subjects and the way you work as to what is best for you. I used pen/paper in my arts courses because I didn't need to get down everything the lecturer said (more themes etc), whereas for law I just try to get down as much as possible, and I find typing quicker (and easier to read later).