What a bizarre turn of events we have here... It seems that everyone who has a new Macbook, Macbook Pr, or Macbook Air and wants to jailbreak there iPhone is in for a surprise. You will be unable to do so. New Macbook owners will notice an iPhone or iPod Touch will not be detected when it is booted into DFU mode, which we all know is key for jailbreaking.
At first I thought that Apple had to make some sort of hardware change within their new Macbooks. Then Dieter politely gave me the version of iTunes running on his new Macbook, 8.0.1 (12). Now the version that everyone else has on their older Macs is version 8.0.1 (11). Very interesting. If it's a simple software change that would only slow down the Dev Team for a few days until a new work-around is found.
Now keep in mind this is not the first attempt by Apple to slow down jailbreaking. A few months back they attempted a counter strike when firmware 2.1 dropped, only to have the Dev Team find a solutions merely days later.
On a side note, I've seen a lot of people having issues with jailbreaking lately, please keep in mind if you do not have a new Macbook, you still can jailbreak. There was a rumor going around on the forums with members concerned they can not jailbreak. This is simply not true.
(Thanks to Landon for the tip!)
[Note: Anyone not using a new Macbook, but looking for help Jailbreaking, check out Jeremy's awesome guides for Mac, Windows, and iPhone 2G, and if you need extra help, drop by our Jailbreak Forum! - Rene]