The only way of watching DRM-protected content on your TV that I know is by connecting video out of you graphics card and audio out of your sound card with your TV. It is simple and you can watch video on your computer and your TV simultaneously.

I don't really know how to re-broadcast DRM protected Windows Media streams. And it is not possible to watch DRM protected streams on your Xbox using xbmc.

The whole concept of DRM is not to allow you to watch content where you want and how you want. It is better to use content providers that don't protect content with DRM.