One of the coolest features of Grand Theft Auto IV was the ability to instantly purchase music you heard in the game without leaving Liberty City. The upcoming "Lost and Damned" DLC will offer the same feature, but with a vital change: The tunes won't be coming from Amazon's music service. Instead, they'll be coming from Apple's iTunes.
Although Rockstar Games hasn't publicly announced the reason for the change, it's probably because iTunes is a more widely adopted service than Amazon's. One of the reasons Rockstar chose Amazon had to do with the company offering MP3s that were not "locked" with Digital Rights Management.
Now that iTunes is doing away with the DRM, it's not a problem. Since iTunes is used by a lot more people than Amazon's service, more people are likely to buy music, so Rockstar and the artists will make more money. Basically, everyone is happy -- except Amazon, of course.
I download through iTunes, so I'm pretty psyched... but I didn't use the song downloader when I played through GTA IV. How about you?