Steam has slowly became one of my favorite gaming services. It has made managing my games so much easier. When I put together a gaming rig, I just install Steam, and it will make sure that all of my games get back on my computer, and that there aren't any licensing issues. I've thought on more than one occasion that it would be awesome if my other apps and even media were handled just as easily. According to Valve's Doug Lombardi, they're thinking along the same lines for digital media.
...we're also looking at other types of content like video and music. We're definitely having those conversations and meetings, and we're reaching out to folks with other types of digital entertainment. I think before the end of the year, you'll probably see some pilot programs with other digital entertainment on Steam.
I think it would be exciting to download music and video from Steam and not have to worry about the DRM that can make switching to a new computer a pain. If everything is handled the same way it is with games, there wouldn't be any reason for me to keep sending my money off to the iTunes store.