I've been following a project that is almost nine months old called CenterStage. It's aim is to become a media hub of your home entertainment system, tying together all of the different types of media that your Mac already plays so well but making it more presentable for your set. I first tried it as a way of playing content on our Mac Mini– it was a very early version and it worked, sorta. It's an ambitious project and I'm eager to see it mature into another open source project.