User blog comment:Master Sima Yi/Assassinews 17-02-'11 — The Da Vinci Disappearance announced/@comment-1769253-20110224180626/@comment-1769253-20110224181830

at the end it says additional 2 hours of single gameplay and extra multiplayer content (3 maps,4 modes & 4 characters) and The Da Vinci Disappearance is the only DLC who includes 4 characters and I doubt that they made an exclusive DLC for PC.