Details are sparse at this point but the linked article has a video demonstrating the vulnerability being exploited. According to the article, this vulnerability a) affects even fully up-to-date installations of Adobe Acrobat b) with Protected Mode on and c) with Javascript disabled. Additional details are sure to come but, for now, be extremely cautious with PDF files.
http://arstechnica.com/security/2012/11/zero-day-attack-reportedly-pierces-key-adobe-reader-defense