"I really have no idea who else to ask about this: Given that most of the new HD-DVD and Blu-Ray players will be at least theoretically capable of outputting an HD signal over component cables, it seems odd to me that all the upconverting DVD players only offer the upconversion over HDMI. Are there any that offer upconverting over component?
Hell, maybe they all do, and I'm just misreading the specs... but if so, I blame the specs."
If you can get high definition formats to output at 1080i or 720p via analog connectors, why not existing DVDs? One word: DRM.
Thanks to CSS, the predecessor to the AACS used on Blu-ray and HD DVD, output of protected content at higher than 480p is restricted to protected digital outputs (DVI and HDMI w/ HDCP). Otherwise they could output standard DVDs upconverted via analog, but they won't.
As we all know CSS was cracked so it may be possible to play unprotected content at higher resolutions, but the player would still have to support it. This is one of the things we touched upon previously in noting that AACS is arguably better than CSS for consumers, with or without ICT. Of course, ICT could prevent you from getting the extra resolution you paid for, instead of just enhancing what is on the disc, which your TV or an external scaler can probably do anyway.
Update: The HVD2085 reviewed here can upconvert even protected content to 1080p via anolog, as well as a couple other players (most requiring hacks). Apparently some Chinese manufacturers have gotten around the CSS restriction, but I haven't ben able to find out specifics yet.