Looks like someone has released an open source toolkit called TiVo File Decoder. It's a command-line utility to convert .tivo movie files to normal mpeg files. It uses your own media access key, so it basically mimics what the TiVo Desktop Software does, but goes another step beyond to remove the DRM. This would allow you to view your TiVo recordings on other unsupported platforms (linux, mac) as well as other devices (cellphone video player, iPod, PSP, etc).
Of course, it requires a Series 2 TiVo in order to function, since all the TiVoToGo functionality is turned off on Series 3 boxes. [via engadget]