I would NEVER buy that Apple thing. I haven't yet found a piece of Apple hardwear that I like (except maybe the Newton back in the day). I do very much like OS X, but not enough to use such a piece of garbage.
My laptop has a 12" screen. Its resolution is 1400x1050
Apple Air is 13.3" with only 1280x800.
My SMALLER screen has 50% more pixels. Having a high resolution is key for productivity and it also makes videos and images look much better.
I HATE those touchpads. They're easier to use initially, but if you spend the time a eraser point is MUCH better for long term use. I prefer the eraserpoint to even regular mice. I've used touchpads and eraserpoints extensively, and there's just no comparison.
I know it can do multitouch, but I consider that to be totally useless.
One USB port? No microphone input?
In my opinion, that laptop is a toy. The design is beautiful and the operating system is great, but it can't compare to a Thinkpad, which is the most functional laptop available.