The list of games available in the plan mixes AAA titles from years past with independent games. Right now you can play games like BioShock, F.E.A.R. 2, Prince of Persia 2008, Tomb Raider Underworld, and smaller indie hits like The Maw, World of Goo, and the appropriately-named AaaaaAAaaaAAAaaAAAAaAAAAA!!!
OnLive promised a "growing library" upon the announcement of PlayPack, but we haven't heard a goal of how often new games will hit or how many they hope to have within this calendar year. For subscribers, the hoped-for answers are "frequent" and "hundreds."