There's been some speculation amongst the mac web about a codename ("Brick") associated with the upcoming MacBook update.
The name originates from
9to5Mac, apparently based on the same Asian sources as the
"rainbow" iPod Nanos.
The "rainbow" iPod nano rumors were apparently misinterpreted as multi-colored individual iPods, but in retrospect, it seems the term instead related to the colors of the rainbow that the new iPod nano are now available in.
Since then, the site has been told that the new MacBook update
will be 'all about the Brick'. The exact meaning of which is left up for debate.