Activision has detailed and dated the final rounds of DLC for Modern Warfare 3.

The new content will arrive first on Xbox 360 in the form of Collection 3: Chaos Pack on August 9 and Collection 4: Final Assault on September 6. Both packs will be priced at 1,200 Microsoft Points (£10.28 / $14.99).
DLC release dates for Call of Duty Elite members weren't detailed. PS3 owners should be able to access the content a month after it hits Microsoft's platform.

Chaos Pack offers extensive solo and co-op gameplay for the Special Ops enthusiast, featuring four brand new Special Ops Missions - Vertigo, Arctic Recon, Light 'Em Up and Special Delivery - and Face Off maps - Vortex, U-Turn and Intersection. Introducing a new way to play Call of Duty, Special Ops Chaos Mode delivers a frenetic form of combat that demands players to outlast waves of enemies, while chaining kills on maps littered in power-ups to achieve the highest possible score on fan-favorite multiplayer maps Resistance, Village, Underground and Dome.
Collection 4: Final Assault is tailored toward hardcore multiplayer fans, and features five all-new multiplayer maps. Gulch sends combatants into a forgotten mining town with mine shafts and equipment sheds for cover. In Boardwalk, fun in the sun on the Jersey Shore means facing enemies on the beach. Offshore and Decommission will test players' sea legs on deadly oceanic oilrigs and among a maze of rotting ocean liners respectively. Rounding out the collection is a trip to the French Quarter in a war-torn New Orleans, where Parish pits players against one another amidst the city's rubble.