In reply to:
Firewire is a lot more flexible because it's just a serial digital standard for high bandwidth applications. It' doesn't much care what information is being carried and it has a respectable amount of bandwidth. DVI on the other hand is a parallel standard, I believe, and only carries video. I'm not aware of anyone using Firewire to transfer video to a monitor at this point but I don't see why they couldn't. It is the digital transmission standard of choice for DVD-Audio, and, as you mentioned, offers some unique network capabilities as well.
Yes, DVI-D is a multi-channel standard (not byte-by-byte parallel, though). I believe that all DVI-D connections currently found in the HT gears is "single-link," which uses 3 "channels" (a channel = pair of copper wires) plus a clock pair; in contrast, the double-link DVI-D for larger computer displays uses 6 channels plus a clock channel.
I see that one nagging problem of both DVI-D and FireWire as they stand today is the cable-length limits -- DVI-D cables are usually limited to 5m (16') due to its high bandwidth (up to 165MHz/channel). One vendor,
RAM Electronics, sells copper DVI-D cables of up to 15m (50') long. But I am not 100% sure about their reliability in carrying a full-HD digital video over a 15m run. I am not familiar enough about the cable length limitations of FireWire, but I believe it is much shorter considering its 400MHz bandwidth. I guess this, along with FireWire's bidirectionality, is a major reason why FireWire has been adopted only as the video recorder interface (besides the multi-channel audio) so far in the HT applications.
The video cable length might be a non-issue for people using a "television" as display device. But it is a real issue for people with front projectors, since the projector is often placed close to the back wall, while electronics are often located along the front wall. In my own case, in order neatly run the cable around the room, I need ~75' of cable run. Currently, the only way of carrying the DVI-D signal over 75' is to use the optical DVI-D extenders -- which cost well over $1K!!!
