So it is confirmed that there will actually be a total of three different downloadable packs for Overlod on the Xbox 360. One will be free and two are labeled as premium, which means we will be paying, no prices set for the premium packs just yet. Get set for some new levels, new multiplayer maps and modes, confirmed split screen co-op action and a new difficulty, The split screen co-op alone is worth the download, I can only hope the prices for the premium content stays reasonable.

From the official press release:

Be extra evil this November as Codemasters announces Overlord: Raising Hell as part of new downloadable content.

One free and two premium downloadable content packs coming soon for OverlordTM on Xbox 360.
Unleashing the wondrously evil Overlord and his army of lethal minions for a fresh round of malicious mayhem, Codemasters today announced the forthcoming release of three downloadable content packs for Overlord™, the summer’s hit action adventure from Triumph Studios.

The all-new content will be available this November from Xbox LIVE® Marketplace for the Xbox™ 360 video game and entertainment system from Microsoft® and comprise of one free and two premium download packs.
The premium downloadable content is led by Overlord™: Raising Hell, an expansion pack that adds all-new single-player levels to the original game. An additional premium pack, the Overlord™: Challenge Pack will deliver a set of all-new online multiplayer maps. Microsoft Points pricing for the two premium content packs will be confirmed at launch. A further downloadable content update will also be available free of charge. This will add split-screen play to all the original game’s multiplayer maps and introduce an all-new multiplayer Survival map.

Premium and Free Downloadable Content Details:
OVERLORD™: RAISING HELL - Premium Downloadable content
Prepare to go deeper into the Overlord’s twisted world as this single-player expansion pack opens a series of hellish new levels. Complete with new enemies and objectives, each new level is a supernatural abyss - a hell for each of the game’s five kingdoms: Mellow Hills, Evernight, Heaven’s Peak, the Golden Halls and the Ruborian Desert.
Access to each abyss is via a portal, which opens once a kingdom has been successfully conquered and the previous ruler banished to a personal hell within. However it’s not just the fallen heroes that have been dragged into the abyss: the Overlord’s newly loyal peasants have also been taken down into hell too.
With the undead denizens of each abyss on the attack and threatening the Overlord’s reign above ground, there’s only one thing for it: assemble your minion army, descend into each abyss and embark on a fresh wave of tyranny in order to return the serfs to their homelands, defeat the fallen heroes once and for all, and claim the throne of each kingdom’s underworld.
OVERLORD™: CHALLENGE PACK - Premium Downloadable content.
This additional premium download content pack is ideal for Overlords who really have something to prove. There’s pillaging fun with seven new online multiplayer maps, including the competitive ‘Capture the Maiden’ map and ‘Protect Your Power’, where players must defend the Overlord’s tower against waves of enemy attack.
Putting minions through their toughest workout, the Challenge pack also introduces a “Legendary” difficulty mode, which challenges players to achieve Legendary status by using their most aggressive minion managing skills to complete the game under exceptional bad-ass circumstances.
OVERLORD™: SPLIT-SCREEN MULTIPLAYER PACK - Free Downloadable Content.
The free update will be available alongside the premium packs and will enable players to go head to head in an all-new split screen multiplayer mode. In addition to providing split screen play on all of the game’s original multiplayer maps, the update will also introduce a new multiplayer map, Rocky Race, which sees a pair of Overlords working cooperatively to survive the onslaught of an arch rock giant on the rampage.
All three content packs are set to be available this November from Xbox LIVE Marketplace for the Xbox 360, with Microsoft Point pricing to be announced. All three packs require players to have a full copy of Overlord for Xbox 360 in order to experience the additional content. For all the latest information and videos, be sure to visit www.codemasters.com/overlord