As routine before an Apple event, such as the one planned for the 14th of October, a slew of rumours are doing the rounds as to what is set to be announced. The latest doing the rounds referrers to something called the 'Brick', although what that is has become a matter of debate. I've got my suspicions though - see below.
Currently the most likely candidate, according to 9to5Mac's sources, is a new manufacturing process which uses "3D lasers" (as opposed to those lowly 2D ones) and water jets to carve MacBooks out of solid bricks (hence the name) of aluminium. 9to5Mac has a pretty good reputation for getting its information from reliable sources.
There are definitely tangible benefits from thus proposed manufacturing advance, not least of which is the inherent improved structural rigidity gained from using a single piece of metal, rather than welding or screwing several together. A fringe benefit of that is the elimination of seams and joins from the finished piece, making for a more attractive chassis, too. Although, of course, the lid is still going to have to be separate still - unless Apple has bade some kind of magic super-flexible aluminium to replace hinges.
All will be revealed next Tuesday, but until then feel free to speculate to your hearts content as to what Apple has planned.