TivoCommunity.com has a thread on stretch modes. It appears that you have a choice of black or grey panels in the non-stretch mode. There is much debate about whether it's better to let the HD-TiVo do the up-conversion and stretching or whether it's better to output a "native" signal and make your TV set do the upconversion and whatnot.

My concern, from reading these threads, is that I don't want to have to tweak my TiVo and my TV every time I change the channel. I want to set it up once and just sit down and watch TV. This may not be easily possible.

Meanwhile, I checked on when I might be getting my HD-TiVo. My order number with ValueElectronics is 13460. That means I'm now approximately #800 in the queue. Based on the vendor's estimated dates for receiving new inventory, I'd be lucky if I got one from the May 28 allocation. Most likely, I won't get one until June. Hopefully, by then, they will at least have the first software upgrades finished...