Bungie has no plans to create any DLC for Halo 3: ODST, as the developer views the expansion as "the final exclamation point" of its efforts to stretch the iconic brand.
"These days we've got a smaller team focused on finishing the ODST campaign and all it entails while the rest of the studio continues making progress on other, larger, secret projects," community director Brian Jarrard told IGN.
"Overall though, we are viewing the ODST campaign and the included multiplayer maps as the final exclamation point in our ongoing efforts to extend the Halo 3 experience.
"We're really grateful to our fans for standing by Halo 3 for so long and continuing to show us such strong support," he said.
Bungie's currently putting together a Mythic map pack that will have three extra levels: Sandbox, Assembly and Orbital. These will be stuffed in the collector's edition of Halo Wars later this month for free, before they're released on Xbox Live Marketplace shortly afterwards.
Plus, added Jarrard, there will be some new Achievements to earn based on these, as well as the endless possibilities of the Halo 3 Forge tool.
Halo 3: ODST launches exclusively for Xbox 360 this autumn and will include some extra multiplayer maps of its own. Halo 3: ODST owners will also be able to play Halo 3 owners online, because both games are part of the same family.
Head over to our our Halo 3: ODST gamepage to find out more.