Is there such a thing? I mean a DVD recorder that wil record an HDTV signal? How about something with DVD Audio capability, or am I being too silly? How about cost?
Nope, no HD recorders yet except for one Zenith hard-disk only HD PVR for OTA only. The DVD recorders record 480i analog interlaced SD video only, like a VCR. You can record a down-converted widescreen 480i analog output from some HD STBs, but its not HD.
Nothing in North America yet. There is the Sony Blu-Ray but Japan only at this point, and priced equivalent to ~US$3800. They haven't announced any plans to bring it to North America; maybe they are waiting for a HD-DVD standard to emerge.
If you want to record HDTV, the hard-disk based PVRs by DirecTV/Tivo, Dish, Motorola, & Scientific Atlanta coming out over the next half year or so are your best bet. Which one you can use is limited by which sat / cable provider you choose.
There is also LG/Zenith but OTA only; new one may also handle unencrypted QAM for digital cable. But the existing one is expensive, low capacity, and can't play back previous shows while recording a new one.
It's technical. In order to pack the increased amount of data to store HD onto the same sized disc, they had to go to shorter wavelength blue lasers rather than the red used with current DVD. They've also been fighting over which blue laser format to use, Sony's Blu-ray or a competing "AOD" spec backed by Toshiba & others. AOD recently won the DVD forum's decision as the official DVD successor, though of course Sony could still try to plow ahead with their format.
And certainly there are copyright issues(not "copywrite"; think "right to copy") to be hashed out.
"Advanced Optical Disc". I think most people are guessing 2005. For more info, read this article.
Initial units for AOD won't record, supposedly. Hard disk is a much better medium for recording high-def anyway, IMO. Unless you want to archive, which is of questionable legality.