Only music already available via the two services are included in the playlists, but Rockstar hope to "add the original songs" created for the games. Only want to listen to the commercials?
The studio has also collected a repository of all their tongue-in-cheek fake commercials and put them online as well. They're available at the Advertising Council website.
The huge collection of playlists is available over at Rockstar's Newswire. Suddenly music seems rad again.