well, when i bought mine i said... well, since i have it maybe i'll dive off into iMovie. well from there it has heavily progressed to FCP HD and a soon to be powermac. The superdrive, and having the ability to burn dvds, is part of the reason. I love it because i've been able to do so many things with it. I made my parents a DVD slideshow for their 25th wedding anniversary. And my girlfriend loves it when i pile pictures together of us that we've taken over the past couple of years and burn them to a DVD as a slide show for her to play at her house, because she doesn't have a computer worth a crap, or to show other people how wonderful her boyfriend is to her. I mean, we send slideshows to her grandparents who live out of state and stuff like that too. And i've even done some slideshows for a class project that i played on the DVD player instead of having to hook up my powerbook and then fiddle with the projector settings and things like that. It REALLY is worth it in my opinion, even for a new switcher. I mean, you do what you have to do, but backing up files is by far not the sole reason for a superdrive.
hope that helps...