I'm a grad student, run around all the time from teaching to office to home to girlfriend's house to train to...you get the point. My iBook G4 also needs replacing.
As a
primary computing device, as a MacBook can be for many people, the Air will fail. But that's fine, because that's not what it's
for. It's designed for people who have a Mac Pro or iMac at home, as I will soon. I would love the Air, carrying around my laptop in an interoffice mail envelope is the prefect camouflage against library laptop thieves! And hey, if I lose it, it'll just get mailed back to my office
Seriously, though, initially I was disappointed with the meagre 80 GB hard disk offer, but then I thought back to my decision on iPod. If an iPod battery lasts 8 hours, is there much point to having an iPod that can hold 5000 hours of music? No (unless you travel without your music source, but I suspect that this is not the case for the vast majority of iPod users). So, assuming that you have your permanent files on a primary iMac, you'd only likely move some choice music, maybe some photos and working files over to the Air. If you're the kind of person who needs instantaneous access to 5 TB of data from an airline seat, well, I'd like to meet you because I think you're a myth!