The thing about buying the iPad is it's supposed to fit IN to your lifestyle, not have to make you shift things around to MAKE it fit in. I could see the iPad being the perfect alternative for a laptop for a Literature major, or a History major, but doing as something as technical as Civil engineering means that you don't have the luxury of relying on handwritten notes on a device that's meant to be used for entertainment or light productivity.
I've fallen into this mentality before (and now I'm doing it every day with the advent of the iPad 2 announcement), but at the end of the day, I don't need to ruin my productivity with a fun device, but need a working laptop for my stay in college.
And if that doesn't help, just think of it like this: the iPad 6 will be out when you graduate. Then you'll have plenty of time for a "play" computer and a "work" computer
Edit: I see a lot of university students chiming in here saying that the iPad works fine for them. My question is, what are you majoring in?
Good post btw. For the sake of the question, Visual Effects BA (which requires software mostly dedicated to PCs with powerful specs) and the odd history lectures here and there.
iPad doesn't fit so much into the path of finishing my degree, it helps ease away from all the concentration/constant workflow during the week. This way, I can have a break from hardcore techonology, whilst being in a comfortable position and still being able to access any basic area of work.