The risk with building a better mousetrap is that, sooner or later, someone's going to come along with a better mouse.
Early and unconfirmed reports indicate that the new aluminum MacBooks have trouble running the Pwnage tool, to the extent that they don't seem to be able to recognize an iPhone or iPod Touch when it is
booted into (jailbreaking-necessary) DFU mode. Mind you, the app itself runs fine — and if you have pre-modified firmware on another Mac or Wintel machine, you can 'restore' your handset to its previous jailbroken state. What no longer works on the metal MacBooks is creation of modified firmware, which is the central purpose of the Pwnage tool.
Opinions differ as to whether a hardware or software change is the culprit, with some fingers pointing at a new implentation of iTunes. One thing's for sure, though — the Dev Team now has their work cut out for them.