I've found Ars Technica to be a good resource for a lot of these sorts of issues.
Here's a quick search if you want to poke around some.
http://arstechnica.com/search.ars?search=vista+drm
Primer on the DRM at the heart of the issue
http://arstechnica.com/articles/culture/aacs-tentacles.ars
Ars Review of Vista
http://arstechnica.com/reviews/os/pretty-vista.ars
Cable Cards and Vista
http://arstechnica.com/news.ars/post/20061128-8300.html
Here's a quick search if you want to poke around some.
http://arstechnica.com/search.ars?search=vista+drm
Primer on the DRM at the heart of the issue
http://arstechnica.com/articles/culture/aacs-tentacles.ars
Ars Review of Vista
http://arstechnica.com/reviews/os/pretty-vista.ars
Cable Cards and Vista
http://arstechnica.com/news.ars/post/20061128-8300.html