Seems that people who got the DVD version can fly CoD now. I'm can only assume that they found an issue with the CD-Keys that came with hard-copies and decided to run another batch of keys. I know that with Steam if you buy a game and the key doesn't work they can issue you with a new, provided you take a photo of the CD Key on the packaging as proof.
If you got the digital version then I guess your going to have to wait for Steam to unlock the game. When I bought Dead Space 2 as a digital download I had to wait 2 extra days compared to people who got the hard-copy. No big deal for me but I can understand being impatient for CoD