I do not have any real experience with Linux, but for a long time I have been thinking about building a home theater PC and I really do not believe that Window Media Center is a terribly impressive OS for that purpose. I have read snippets about there being a Linux OS that is designed for the purpose, but I do not know much else. My intention is to see what it would cost to outfit the box with a CABLECARD and the drive you need to use one.
If you do not know what the CABLECARD is it is an ASIC type card which decrypts the signals from your cable company just like your cable box does. The CATV industry was supposed to make available years ago so that they would not be able to continue ripping off their customer with piratical monthly fees for DVR’s and Cable Boxes. They managed to have their lobbyists squeal about security for years to avoid having to obey the law, but you can get one from the Time Warner office if you ask. It will cost 1.75$ per month, which is roughly the same price for a year as my DVR costs for a month. You can buy some very expensive TV’s with CABLECARD slots and it is to be assumed that they shall become widely available once the electronics industry can make them at a lower price.
Obviously the big thing with a Home Theater PC is having an OS which works the way that your DVR or cable box does. It needs to have a schedule that will tell you what is going to be on and allow you to easily record shows that you want to watch. I honestly do not need it to do anything else as I have WDTV which very simply plays files off my PC or external drives on my stereo or TV.