Apologies on the broken link. It is fixed now.
We haven't had a chance to look at the Windows PVR solutions. If WinMyth is functionally similar to the Linux version, it will probably be quite easy to get it working. There are only 2 devices involved, and they are both quite small: The MythTV-Plugin is the plugin which is loaded into the DCE Router and handles the communication with the mythbackend, and coordinates everything with all the players. The MythTV Player is the DCE device that runs on the media pc itself and communicates with the Myth Front end.
There's not a lot of code (less than 1,000 lines), and in both cases, 90% of the code is generic. In the Plug-in, much of the code is building the datagrids to show the program guide. If WinMyth uses the same database schema, that code will work the same without any changes.
So, I think it will be really easy to get it going with WinMyth. However, our focus right now is on finishing up the Linux implementation, since we still have several missing pieces. We'll be able to put more attention to the Windows aspects in about a month or so.