Updated: February 29, 2012

Fourzerotwo just announced via Twitter that NON-Elite Premium members will be able to purchase all available contents drops #1-6 on March 20th on the Xbox Live marketplace.
A few minute later he also confirmed that ELITE Premium members will be getting content drops #4,5,6 (Blackbox MP Map, Spec Ops Mission “BlackIce” and “Negotiator”) on March 13th.
DROP 4: BLACK BOX MP Map


Battle beside a downed Air Force One in “Black Box.” Multi-level homes overlook the neighboring streets, creating a deadly kill zone for players on the ground. With clear sight lines from house to house, however, snipers are far from safe, with counter-sniping an ever-present threat to their dominance. Those that prefer close-quarters combat can succeed in the tight confines of the crashed airplane or in hunting down enemies posted up within any of the surrounding homes.
DROP 5: BLACK ICE Spec Ops Mission

Shred ice from aboard your snowmobile as you infiltrate a diamond mine in the Special Ops mission, “Black Ice.” Melt more than snow when you plant high-grade explosives to shut the mine down forever.
DROP 6: NEGOTIATOR Spec Ops Mission

Cash in all your karma as you head to India for high-stakes hostage extraction in “Negotiator,” an all-new Special Ops mission in which you’ll breach-and-clear rooms and navigate surface streets to secure the safety of your VIPs. This marks the first time Special Ops has been made downloadable online in franchise history.
SOURCE: @Fourzerotwo