Talking of music: "We can't confirm the balance between licensed and unlicensed music yet, but everything in the game is evolving, and is going to be changing slightly, and that will include the radio stations I think. But we'll have confirmed details of how that's going to work later on. But I think it'll be a huge and broad spectrum of music that will cover decades; just because it's set now, doesn't mean that the music has to be in 2006 and 2007; I'm sure it will be far-reaching in terms of decades, and genres."
I thought this was a good quote from the Rockstar rep showing them the game in that kikizo preview. It's a bit more than before.
EDIT: @Ash, so that was the background work you were talking about. It'll be interesting to see how GTAIV relates to those.