I wondered how they/he had tested the battery life as well.
This is one reason I am still hanging onto my 13" iBook. The ~8 hours of battery time I have yet to see in any other "ultraportable" laptop. It's still not heavy to lug around, and for anything the 800MHz w/ 640MB of RAM can't hadnle, there's always VNC and SSH to get into a more powerful machine - which it seems the MacBook Air is still relying on you having another server/desktop anyways.