Leave it to the guys at iFixit to get a new MacBook Air and, instead of showing off at the local coffee shop (like us), they take the thing apart. The company specializes in Mac and iPod parts and repairs, but it is perhaps best known for taking every new Apple product and dissecting it. They then post step-by-step photos and a detailed analysis of the parts inside.
From iFixit's photos, we see that the battery is the biggest internal component by far. It is held in place by nine screws, in case you were thinking about replacing it yourself. Like the iPod, the 80GB hard drive is protected by both a rubber bumper and a layer of foam (similar to what we found when replacing an iPod hard drive a couple of years ago). The custom Intel CPU is protected by an unusual thin aluminum heat sink--necessitated by the laptop's slim design.
You can check out the dozens of detailed photos, and a piece by piece count of the 88 screws that hold it together, over at iFixit's MacBook Air autopsy.