(I read this from a guy on the official black ops forums. I have nothing to do with this. Im just sharing info i that i heard recently.)
Apparently you already have the First Strike DLC. How you ask? Well, that pay and play file has all the maps loaded onto it. It's unable to be used however. Treyarch has to activate it. Possibly for approval or something. Check it out urself if u want. Put the pay and play file on a sd card and put it in ur computer and u'll see it. It's nice to know that treyarch are still doing something for us!!