The two HD formats are a very interesting subject for a number of reasons (and very frustrating). First, the standard for output from them has not been clearly defined, making it effectively impossible for anyone to design a receiver or processor that can guarantee support for them. (Which may be related to Toshiba's very recent decision to push the HD-DVD launch into early 2006, around the same time that Sony will launch Blu-Ray...)

HD-DVD has said that the component video output will be limited to 480 (I'm not sure if that will be 480p or 480i, but either way it essentially makes the component outputs useless for HDTV's). Blu-Ray hasn't said either way, but is likely to do the same. That leaves the true high definition video in the digital domain (HDMI output to either a DVI or HDMI display). The audio output will be by HDMI in some form (presumably HDMI 1.2, although as I mentioned in the HDMI 1.2 thread there was no specific mention of either Dolby Digital Plus or DTS-HD in the HDMI 1.2 announcement). The specifics of the audio output have not been well spelled out at all (I've looked for those specifics for months now). We know (because of the specifications for DD+ and DTS-HD) that downmixed DD and DTS audio will be available from coaxial or optical outputs, just like existing DVD's. Personally, I also expect that most players will include analog decoders that are functionally identical to the Dolby Digital decoders found in early DVD players, with a 7.1 analog audio output available to support the huge installed base of DD/DTS receivers and processors (including the Model 990). The Model 990 will not be able to accept a digital signal carrying DD+, DTS-HD, or MLP lossless, but so far I've seen nothing that would suggest that a multichannel analog signal would be forbidden - which means we should be able to get those DD+ and DTS-HD soundtracks through the 990 and on to our ears. The only obvious exception to this is the PS3 - it will apparently support playing Blu-Ray movies, but lacks a multichannel analog output, so the only way to hook one up to a Model 990 would be via the optical output (which means downmixed DD and DTS audio).