Just wait. I know how one can get antsy with wanting to buy a computer.
Like stated previously, most (if not all) schools have strict guidelines for student computers. From what I have seen, most are not Apple friendly. Even then, the school's requirements are going to surpass the Air's capabilities. For example, East Carolina University's program will require students have 3 Apple products - Macbook Pro, iPad, and iPhone/iPod Touch. The Air simply does not have the processing power needed to provide excellent and seamless performance.
Now disregard everything above and you still want an Apple product? I would wait until next year, because Apple likes to release new and updated product lines right before the new school year. Plus, the Macbook Pro (13 inch) is the best bang for your buck in my opinion.