By the way, I've got a 13" MBA for school and it's perfect. I decided to get the 13" over the 11" for school for two important reasons: the longer battery life, and more screen real estate. Battery life is very important as on the 13" MBA you get on average 2 hours longer than on the 11" MBA, and the screen on the 13" offers more screen real estate than the 11", which had a weird aspect ratio, in my opinion. The fact that I just couldn't get used to the aspect ratio on the 11" and the longer battery life on the 13" is what caused me to buy the 13" and I don't regret my decision at all.
Also, not to mention that the 13" is faster and has a full size keyboard, while the 11" has smaller function keys. Just some added bonuses if you ask me.