According to leaked footage, it would appear that a certain Call of Duty: Black Ops post-completion unlockable is one for the history books. In this image, the identities of the four-man zombie hit squad are strictly classified -- head past the break to spoil them. (Consider that fair warning!)
Spoiler alert: Video contains game ending (skipped in embed) and unlockable content footage.
Update: While the video has been pulled from YouTube, details about the spoiler can be found in this Zombie Zone News post, with screenshots (from the video). Once you click the link, there's no avoiding the spoiler. (Consider that fair warning.)
Call of Duty: Black Ops is a first-person shooter with stealth and tactical play aspect that puts players in the role of a shadow soldier fighting in a variety of historically representative fictional Black Ops missions of the Cold War era. Created with the input of actual Black Ops soldiers from the time, the game mixes traditional Call of Duty tactical shooter gameplay with new gameplay options designed to expand the players' experience. Additional features include extensive multiplayer options, along with new vehicles and explosive new weapons.