Jeremy Toeman over at LiveDigitally talks about the "living room effect" that can convince even the most hardened skeptic to make the move to HDTV.
I'm a big proponent of experiencing products in order to understand their impact, but there are certain things that even a demo can't cure. I find this uniquely interesting on a personal level because the "living room effect" hasn't proven to be true here, at casa HomeTheaterView. I've had a 53" LCOS HDTV for 2+ years, but reception is over the air (when we get it - it can be flaky), and our ReplayTV is hooked up to the analog cable feed. I refuse to watch SDTV when HDTV is available for the reasons Jeremy cites, but my wife is equally adamant that she will not watch content live with commercials. HDTV encompasses more than one improvement to TV watching -- dramatically higher resolution, digital surround sound, and a widescreen aspect ratio. But my wife prizes one feature above that, her time, and would prefer to watch fuzzy contents and save 18 minutes an hour rather than bask in the glory that is HD.
My wife may be somewhat unique, but there are plenty of TV-loving consumers who have priorities that preclude HDTV at this time. HDTV up front costs are high; HDTV has come way down in price, but sets are still fairly expensive. Ongoing costs of HDTV can be considerably higher than analog, depending on the technology used to recieve the signal. Cable HDTV requires upgrading to a digital package and renting a set top box; some cable and satellite providers charge separately for HDTV channels. And a lot of content - the vast majority of cable channels - is unavailable in HD, so if that's what you watch, buying an HDTV won't make things better (and in some cases, it'll look worse).
A TiVo series 3 may be in my future. I have asked TiVo for a unit to review here; hopefully one will show up soon, and my wife and I can watch TV together again.