I have been doing lots of searching because TiVo's are expensive and a HTPC isn't really cheaper. Plus, HTPCs are lacking parental controls. I was keeping an eye on Moxi a while ago, but they were purchased by ARRIS.
*If you don't want to ready the story, proceed to the end.
So. Ceton and HDHomeRun have "Ethernet" tuners where they take digital TV streams and make it accessible over the network. The downside... due to the whole copyright thing, you can only access the encrypted channels via Windows Media Center.
I have been doing lots of research and it would be possible to build your own Linux powered system but it needs to be certified by CableLabs. They have 86 pages of specifications, regulations and protocols for a device to get certified and allowed to access the encrypted channels. Certification can cost $70k- $100k and take 6-8 weeks and then a license fee of .07 per device and $20k a year to manage the licenses.
I want a simple TV tuner for the kids with parental controls including time restrictions or bedroom that can pause TV for 30 minutes with a clutter free guide and the ability to play Netflix and various other video formats.
*Read here if you wanted to save 2 minutes
You would be interested in a mini DVR that costs maybe $125 with an annual fee under $25?
One thing to consider, you would still be required to purchase the Centon/HDHomeRun tuner ($130-300) which would be an additional expense, but would make future upgrades cheaper.
Future versions would be a full scale DVR with the ability to record multiple programs at once and maybe a video server to play DVD and CD backups across the network.
I was thinking of trying to use crowd funding to get off the ground.