Space around my TV is already at a huge premium, so don't have room to squish in an HD receiver. As it is, I have my TiVo standing on its side next to the TV, mostly due to the poor airflow in my rack. My TiVo stays nice and cool now, but the noise from it is annoying.

Part of me wants to put a bigger / quieter drive into the TiVo, while the rest of me knows that, hopefully in time for Christmas, I'll be able to swap out my current DirectTV/TiVo box for an HDTiVo. I have a $5 bet with a friend riding on whether TiVo actually ships before Christmas or not. I'm betting they do.