The original black MacBook was great, but it was made of plastic. the aluminum MacBook Pro is great, but it's silver. According to MacRumors, Apple might be combining the two ideas to create a MacBook Air whose aluminum shell has been anodized black.
We at Gizmodo are in full support of the black MacBook Air, as 100% of us have lusted over the idea of one at some point or another. At one point, I even considered having my MacBook Pro anodized.
UPDATE: MacRumors got an email from another Apple source who confirmed there was a black MacBook air in the works, but that the black powder coating on the aluminum soaked up to many body oils on the palm rest and made it look nasty. So Apple scrapped the idea (or put it off for a rainy day, at least). Bummer. [MacRumors via BGR]