The 2K Games forums have a number of posts indicating that the long-awaited Protector Trials DLC for BioShock 2 mistakenly showed up in the Games for Windows Marketplace, and while players were able to purchase it (in spite of the fact that it was supposed to be a free release), it does not work at this time, likely because the underwater shooter sequel will require a patch before it will work. There are posts from community manager 2K Elizabeth apologizing for the error, but there's no word yet on any recourse for those who have purchased the DLC. Thanks Big Download.