This got me curious and after a bit of searching and seeing little blurbs, I kinda got a feeling there would be a lot of Rap/Hip-Hop.
Then I found this...
The Current Confirmed Madden NFL 2006 songs:
Slim Thug- Get It Started
Hate in Ya Eyes- Chamillionaire
The Equalizer- Sam Spence
A Golden Boy Again- Sam Spence
Move Around- Bump J
A song from The Game
A song from Disturbed
I also saw a blurb that Spider Loc will have a song on there, whoever he is...and some song from the Fantastic Four soundtrack as well.