Add this to the list of things GTAIV's doing that its predecessors didn't: at least one of the new title's radio stations will feature only one artist, who'll be providing an all-new set of tracks for the game. Hip-hop DJ Green Lantern has told King magazine:
Somebody within my camp said that they were interested in doing some stuff. We sat down and it ended up like a whole radio show. This particular show, there's a little bit of budget involved. It's not the normal licensed-out music. When you jump in the car, you're going to be able to hear a whole Green Lantern radio show filled with nothing but exclusive music I produced for the game. I think it's the first time that's ever been done.
Not the biggest fan of Green Lantern myself (thinking a DJ Krush station would be perferable), but as a concept, it's a good one. Hopefully there's more like it.
KING Magazine Reveals DJ For GTA IV [PlanetGTA]
UPDATE - OK, little confusion here. Mostly my bad. Rockstar have let us know that while Lantern's got his own show on the station - on which every song played is one he's produced - it's not the only show on the station. So there is more than one artist. Sorry for the confusion, but hey, good news is that makes it sound like these stations have a lot of content.