10:08 PT: What is the MacBook Air? In a sentence: "it's the world's thinnest notebook." What does that mean? They went and looked at most of the thinnest notebooks: Sony TZ series, for example. Looked at all of them and tried to distill the best of all of them: ~3 lbs, 0.8-1.2" thin, "compromised on display" with 11" or 12" display, and compromised on keyboard with a miniature keyboard, and they run 1.2 GHz Core 2 Duo. Looked at this and tried to figure what they liked. Weight's a good target, but too much compromising on thickness and less than fullsize display and keyboard, and want more performance.
10:10 PT: Here's the thinness first. 1.20" down to 0.8" in a wedge shape. Holy cow, the MacBook air runs from 0.76" to 0.16" (that's not a typo). The thickest part of the MacBook Air is thiner than the thinnest part of the TZ series. So thin it fits in a manila envelope. Here's what it looks like. And, typical Steve, he's got it in an envelope on the stage (all those case manufacturers are going to be disappointed).