If you think the 2012 MacBook Pro 18mm thickness is the limit then you really make a mistake. According to news report, the next-generation 2013 version MacBook Pro will be thinner with the help of new process.
It is said Apple is developing a new process, if it’s succeeded, it will be able to reduce 0.15mm of the MacBook Pro thickness. This process will directly affect the thickness of the emitting light keyboard light guide plate(LGP), the thickness of the previous LGP is 0.4mm, the LGP using the new production process will be only 0.25 mm. Perhaps 0.15mm thickness reduction does not have much impact to the entire MacBook Pro, but the thinner keyboard may reduce the possibillity of leaving marks on the screen.
It’s sure that the thickness of the next year’s MacBook Pro will certainly not have that much drop, but it is clear that Apple is bound to continue research and development new technology to make the various parts thickness to the thinnest, and finally to make MacBook Pro be able to “thin as cicada wing”.