Any idea if MythTV cares if the signal is HD or not?

I have been eyeing MythTV for a few months now. The second I hear that HD cards are supported, I will be building a box to replace my TiVo.

I was also looking into the Hauppauge HDTV card since it has component video out. However, TechTV blasted it. I would assume that the hardware is fine, it's just the software they didn't like. Does anyone have that card?