I've had my new 11" 4GB/128GB MBA for about a month now. I love it. It is replacing a mid-2010 13" MBP (which I've since sold). The main reason I wanted the Air is because I go to school at night, and the MBP, while small, was still bulky to carry and use on a desk for notes.
The 11" Air is a dream. When it's at home, I have it docked to an HP monitor, which I hope to upgrade to the Thunderbolt Display. I bring it to work with me for meeting note taking, and presentations more in the month I've had it than I did in the 18 months that I had the MBP. It's just so easy to bring with me.
The only software that I've install on it so far is Office 2011 and Xcode. I'm using Word for note taking, but are there more "lecture note friendly" programs for college?