Jan Zdarsa According to AppleInsider Apple is proud of the title of the thinnest laptop in the world, which it has in its stable in the form of the Macbook Air, but currently he is not happy with his weight. So how next? Apple is toying with the idea of making a Macbook Air out of carbon fiber. This material is not only amazingly thin and strong, but above all amazingly light.
The upper cover of the monitor would probably continue to be made of a single block of aluminum, but the lower chassis would be made of carbon fiber, at least the bottom of the notebook. It would made the notebook lighter from the current 1363 grams to just 1263 grams. This is just speculation, but it would again be a development shift, so it certainly makes sense. According to AppleInsider, such a Macbook Air should appear sometime next year. And to give you an idea of how much everything weighs in such a current Macbook Air, I'm adding a table from iFixit.com.
It would require a metallurgical upgrade. Aluminum is nice, but really soft (own experience :-)