I use MS Office, Firefox, Adobe and a few other basic programs and I don't need anything more than what the Air has
i'm currently running all of that, including Adobe Creative Cloud. If you do design, photo, video, music, etc., the educational Creative Cloud is a must-have. $20 a month, and you have software that costs $2500 out of box, and it doesn't go obsolete.
Anyway, i run that on the Air without issue. Heavy video editing would be an issue though--rending nightmare i'm sure. But the thunderbolt drives are plenty fast for serious editing (processor is issue).