Surprise no one posted this yet;
Content Pack 2 will drop on the 22nd of May, but however, if you are an Elite member you will receive the content from Pack 2 on the 15th May. (albiet Elite members already own Sanctuary and Foundation)
Also coming the 15th may is the new game mode "face off", along with 2 specifically designed maps for it - for FREE on 15th may.
So In summary, Content Pack 2 includes:
Face off Game Mode + maps:
Just to be clear on the Face Off Free DLC, it is released May 15th and includes the two maps Erosion and Aground. The other two maps for Face Off, Getaway and Lookout, will only be available if you are a CoD Elite member or if you purchase the Content Pack