I came across this useful Media Center plugin recently. As well as providing an alternate interface to browse media files it also includes an RSS reader which I've successfully configured to watch some interesting video podcasts:
- dnrTV - .NET Rocks TV
- 10-4 – New features of Visual Studio 2010 and .NET Framework 4.0
- TED – Talks from the annual Technology, Entertainment, Design conferences
- Scrap Time – A Scrapbooking video podcast for Narelle
It is free, and is being actively developed on Google Code.