What I think...
There will be the mass market of low quality moderate bit rate music will be downloadable and put on cheap and poor quality phones/music players. This will do for most people and 99% of all music will be purchased as this.
There will be music available uncompressed with 44.1K and better sample rates at a premium for people with hifi. When someone brings out a reasonable server to replace my nice CD player then I might add this as a source - and only if it plays uncompressed music at 192 or 384K, has a remote and excellant quality DAC - though I can pipe the output through my CD player at 384K. I have looked at servers, some are very expensive (1000's £), some are just not very good quality (squeezebox etc). They are also aimed at being clever technology rather then being easy to use and high quality.
The CD quality was a compromise, 44.1K was not good enough to easily produce quality music - but it has become a standard that everyone uses. I believe there are few in the music industry that understands quality/ambiance/phase properties of sound and I have moved away from using music industry music as only 1/10 is of resonable quality - this is a mastering problem rather than the medium. Musician produce music is so much better quality and has been a revelation to me. I am sitting listening to some piano music that might as well be played by my son on our piano - it is that good sound quality - but then my son does not respond to a remote control (in fact, being a tenager he responds very little to what I say
).
Vinyl. This again is a compromised source that depends on the quality of the plastic used for the records, many produced in the 70's during the oil shortage are shocking quality. I have some good quality vinyl, but this again this is subject much more to the quality of the master than the medium used to hold the music. Some of my records sound good, some sound crap and this is nothing to do with vinyl/CD/bit-stream medium.
I do think that digital download will be the future - I do worry about still obtaining uncompressed music though. The CD sample rate WAS good enough for a good CD player, but the new mass market formats are not.
Just my thoughts.
Tom