I don't see what BR will offer that the old formats didn't. I also don't see the labels spending money....again......to remix stuff for 5.1 when it failed the last time.
Big differences in my opinion:
1. 100% industry support for the format. SACD and DVD-A had fractured support with big players missing from both camps. In my opinion, a consumer audio video format that doesn't have support from the industry doesn't succeed, period. Whatever market could have been realized had no confidence either format could survive and of course for good reason, neither could. Why bother with a format like SACD or DVD-A that won't see many releases and can't be played by friends and family?
2. HD video simultaneously with high resolution audio. Neither SACD or DVD-A had any video so Blu-ray can do everything SACD and DVD-A could do and so much more. Audio only releases or combination of audio and video work on Blu-ray. Of course DVD-A could also offer lossy audio and video by inclusion of a DVD-V section or separate disc, but that wasn't nearly as attractive for use with a high quality audio video system, video and audio were both compromised. Blu-ray requires no compromise with capacity and bitrates available to do everything needed.
3. There is a much larger customer base with players already in service, bigger than both SACD and DVD-A combined, and it is growing at a good pace. Consumer products that succeed by reaching a market for use with a product that already existed for another reason are common. Blu-ray has far greater market awareness, people that don't own it now are considering a purchase and I am finding that many people I know that don't own it understand it will replace DVD. Blu-ray is only succeeding by reaching the market that already owns an HDTV. SACD and DVD-A had very poor market awareness and in my experience, when somebody knew about either, the opinion was often negative. Blu-ray is held in high esteem by everyone I know in real life that is interested in home audio and video.
4. The existing mixes for the debacle behind us can be used again, it isn't like a large market already owns the music. New music of course must be mixed and the selection needs to be a multiple of what was available on the older formats. Equipment and personnel already exist to do this work, let them get busy.
I feel certain that Blu-ray will do much better than SACD and DVD-A but I am also certain it can't reach a market as large as DVD and CD did but with both of those declining, these companies all need something to help offset the decline. We still see some LP releases. I don't know the number of turntables in service, but it has to be a tiny fraction of the number of Blu-ray players in service. I know the primary reason for the Blu-ray player purchase wasn't to play music, but that doesn't matter, it works great for that purpose. There is a market for high quality audio and it should be big enough to matter. Why wouldn't they give Blu-ray a chance? When to proceed and how to proceed needs to be worked out.
Chris