Saw this on Major Nelson's site this morning. Sounds really great and makes me wish I hadn't traded it in already:
Think you’ve mastered Kameo™:Elements of Power™? Think again! With expanded co-op action and super challenging gameplay, the upcoming Kameo Power Pack is sure to put your abilities to the test. This downloadable content contains three great new co-op modes of play: Expert Mode, Rune Battle Mode, and Time Attack Mode.
* Expert Mode: Expert Mode features six re-mastered tougher-than-ever levels, for both solo and cooperative play. Be prepared to face battles that will make even the most hardcore Kameo veterans balk. Suited up in their exclusive new Armor Skins, all ten of your Elemental Warriors will be on hand to help you in the enhanced combat...and you’re gonna need ‘em!
* Time Attack Mode: In Time Attack Mode, team up with a friend over split-screen, System Link, or Xbox Live®, and work together to try and beat the clock—and the Trolls—against seemingly impossible odds.
* Rune Battle Mode: Rune Battle Mode turns traditional Kameo co-op on its head, with new VS gameplay that pits you against your opponent—as well as Trolls—in a fight to grab the most runes. Use one of the unique new weapons to thwart your adversary in this no-holds-barred arcade scramble!
The Kameo Power Pack also introduces 15 new achievements and worldwide leaderboards. Check the Kameo community site frequently for the latest news and to see how you can get the Kameo Power Pack for yourself.