Tivo announced a new system that lets you transfer recordings off of your tivo, and onto your computer. Might be mpeg2 format. So that could be an interesting plugin, one that can retrieve shows from your Tivo.
Unfortunately (for me anyway) DirecTivo doesn't support it yet. The easiest way for me to get recordings off the DirecTivo is to hook up a video cable to the capture card and manually record it. <sigh>.
I have high hopes it will be released for DirecTv soon though. In the mean time I'll keep using a PC based PVR as well.