Klae i intend to do the same at college and also have purchased a MBA. i realized that a MBA wouldn't be the best thing for thing for college, but i did realize that it would be great to use during class and in the library. taking notes and going to class with a 2 lbs computer will be great. but i also will be purchasing an iMac for heavier use, i talked to a professor at the university that i will be attending and he said that you will be most likely working with multiple OS's, and a 128ssd wouldn't get the job done. an iMac would have the hours power and storage you will need. that the set up I'm going with.( 13"MBA 2012/i5/8gb RAM/128GB SSD + 27" iMac/24gb RAM/256GB SSD+1TB HDD)
cheers