David Guetta feat. Akon - "Sexy Chick" (Arguably the hardest song in the game tier-wise)
Britney Spears - "Toxic" (NOTE - This is a cover as if we're back in 2006 in terms of rocking cover songs on games. Harmonix I guess didn't get the rights to use the actual song... makes you wander if Britney is really that hard to get in games like these).
Willow Smith - "Whip My Hair" (no surprise that song is in the game)
Lady Gaga - "Born This Way" and "Bad Romance" (Gaga is one of a handful artists that have at least two songs in the game)
More soon... still the Kinect game to get this holiday season (well if you want 4-player dancing rather than two here in DC2, u can get Just Dance 3).