After a whole lot of teasing, Halo 4's first bit of DLC, the Crimson Map Pack, is now available for download on Xbox LIVE. The three-map bundle is priced at 800 Microsoft Points (that's $10) for most, while anyone who has the War Games Map Pass -- basically the Halo 4 Season Pass -- should automatically have the maps unlocked for them.
Bear in mind that if you do have the pass, don't go trying to repurchase the Crimson Map Pack off the Marketplace, because you will get charged for it. And who ever wants to pay twice for something?
The three maps that come with the Crimson bundle were fully revealed at the end of November. There's a varied offering of human and alien environments, with an emphasis on vehicle play. Also, 343i really loves Man Cannons; most of the new Achievements revolve around using them in creative ways.