I think rolling backpacks are a PITA. I just use a regular backpack. I only take maybe 2 books to class a day anyways along with my notebook and powerpoints.
Yes, we have a lot of big HEAVY textbooks and reference books, but you don't need to haul them all to class. That is another reason why I bought my Palm TX---I can bring all my reference books with me (Davis, Tabers, etc) easily.
If you haven't started nursing school I would just wait till after you first week or two are over before you spend money on anything expensive (some people really spend a lot on their backpacks, etc), that way you can see how your classes are set up and what you really do need to bring to class. Some of my instructors don't go by the book at all, some go right out of it.