There are arguments both for and against attempting to use an ipad in place of a cheap laptop. A quick google will turn up ample results.
In summary, a laptop will do everything you need in college, including online research projects and the like, plus you will be more than familiar with its operating system. You just can't go wrong with a laptop.
Conversely, a 64gb ipad + zaggfolio already costs as much as a basic 11" MBA. Pros typically include its long battery life (relative to a MBA anyways) and 3G/4G connectivity, but IOS will definitely take some getting used to when you try to use it to perform traditional laptop tasks.
What else do you foresee yourself doing in college?