The post title says it all. The original “Doom9” forum post was on Feb. 5th, followed on Feb. 11th by a generalization of the original poster’s method. After a bit of informal peer review, including agreement from anti-DRM maven Cory Doctorow and Ars Technica, it looks like the AACS restriction scheme has been defeated.
This breaks the copy “protection” on all currently released HD-DVD and Blu-Ray discs!
So does this mean that the gates are open for Blu-ray and HD DVD? Not quite. The hackers believe that it is only a matter of time before WinDVD’s device key is revoked, which will necessitate a software update for WinDVD owners and set the work of decrypting new titles back to square one. The hackers have been careful not to release the actual Device Key for WinDVD to the public, but as all the hacks to date have been accomplished using software-based players (which, unlike hardware-based players, can be easily updated over the Internet) it seems likely that these Device Keys will be revoked anyway. Therefore, it cannot really be stated that AACS has been completely cracked at this point in time. The new crack still requires a general-purpose method of extracting the Master Keys, which has not yet been accomplished. — Ars Technica