For anyone experiencing problems with the Crysis 2 DLC on PC, please see the statement below;

Direct2game Services for purchasing new DLC is currently not operating. All DLC and redeem codes acquired prior to 1/23/2012 are still working and available for your continued use. We will update you when this situation is resolved.

Feel free to post questions and comments on the DLC here, i'll answer what I can but there wont be much info I can share until there is an update to the situation.