Today after work, sick from El Burrito and bored, I finally got around to putting the ends on the cable and relocating my noisy Tivo from behind my TV to my server closet. I forgot about the IR problem, so for now I have to open up the closet door and bounce the IR signal off the wall, but it works.
Since I already have a server in the server closet, and I have my quiet Roku HD1000 and Squeezebox, I can write some software for either to accept IR signals (documented APIs for both, IIRC) and send them over the network to my closet server, which will IR blast them at the Tivo.
Unfortunately there appears to be some blurriness in the red channel now. Previously I was only using coax into my Tivo, and S-Video out. I might just have to get a 70 foot S-Video and audio cable, if only I were confident that'd help. Maybe I just won't care... it already looks like ass on my TV, analog cable through Tivo MPEG compression, scaled up to 65".
I was also too lazy this wiring project to do anything creative with the cables... they're just running along the edge of the walls and across the hallway (covered with a rug).
But my living room is nice and quiet now! I should get a book and go read in it.