MacBlogz is echoing some of what we've been hearing from our sources.  The recent rumors of a carbon fiber MacBook not only don't make sense from an aesthetic standpoint, they also don't make sense from a materials standpoint.  Our source said that anyone who knows materials science will know it is made up.  Real carbon fiber can't be used in a laptop effectively - while it is strong, it can't be fastened to aluminum or other metals effectively.  MacBlogz echoes this sentiment:

As an engineer who designs carbon fiber parts, I know it’s an amazing material, but it has its limitations. Ultra light and strong organically shaped structures: Yes! Small intricate parts: No. Laptops from Sony and VooDoo claim to be made from carbon fiber, but it’s not the woven type you see on a Formula 1 car. Its merely injection molded plastic with tiny little pieces of carbon fiber in it. One could call it a marketing ploy.

- Anodized aluminum is many times harder than carbon fiber in epoxy, thus very scratch resistant.
- You can easily tap screw holes into aluminum, not into carbon fiber.
- CNC machined aluminum has tolerances down to a few microns, carbon fiber is much less exact.
- Aluminum can be cast, milled and forged into almost any geometry. Carbon fiber cloth is limited by the geometries it can fit around and there can be no sharp corners.
- Carbon fiber cloth must be laid up by hand before curing - aluminum cutting and forming is automated.
- Aluminum is easily recyclable, carbon fiber less so.

Bottom line...  Don't expect a carbon fiber laptop from Apple or trust anyone who says one is in the works.