I'm a student. I use a USB hub. I've used my optical drive thus far this school year. I use headphones. I don't use an external monitor. I don't own anything that uses FireWire.
I work at my school's bookstore. I can't even count on my fingers the amount of people that came in asking if we had any MacBook Airs in stock. Same for the day after. And the day after that.
"Crippled" is subjective. Do you really need that much processing power? Do you really need that many USB ports? Do you really need more internal speakers? If so, you're not within the MacBook Air's target market, which is a group of people that are willing to pay more for a still competent and more portable machine.
Running over 3 miles every day between lecture halls and discussion rooms with my MacBook in my backpack isn't exactly fun for me and I'm sure it's not very good for my back. If I could sacrifice things to reduce the weight (and thickness, some lecture halls are rather cramped) of my backpack, it would be the optical drive that I rarely use, the speakers that aren't very loud anyway, and the extraneous USB ports that I never use.