I stumbled across LinuxMCE, a free competitor to Windows Media Center Edition. LinuxMCE does what WinMCE does except it does much, much more. The features included in LinuxMCE go well beyond the simple Media Center PC.
Media Hub
WinMCE has the ability to catalog and organize your media, which means music, photos and videos/DVDs on the computer on which it is installed. But LinuxMCE has the ability to automatically search your network to find all the multimedia on all the computers in your network. Although I’m sure that means you will need to share your media files on windows computers or setup NFS on your other Linux/Unix machines, that’s a trivial thing to do.