Two channel will only die when people are prepared to exchange quality for convenience. Much the same as vinyl as a source was going to die when CD came on the scene. Some people care about the quality of the sound, as much as they car about the music, one being an aid to the other, (which way round is sometimes hard to tell). MP anything, or its equivalent is a easy to use, and carry, music source, but as far as I am concerned, especially at the lower bit rates, not for serious listening. From listening to my sons friends, it appears my lads are in the minority, as they actually buy hard copies of the music they want, and rip it for use on portable players, others regard illegal downloads as a valid way to obtain music. My Son's have the same feeling as me, OK for CD, while mine is more for Vinyl, but a music collection is just that, it is a collection of music that you enjoyed at the time of purchase, and continue to enjoy years after purchase, it is a lifetimes collection, for a lifetimes enjoyment. Digital downloads seem to more about instant gratification, and probably just as instant deletion.
If things like a Mac and ADM9's encourage people to enjoy music more, it may well be that far from being a instrument that heralds the death knell of two channel gear, it actually encourages people to find out what the alternatives are. Dealers maybe need to embrace digital and use it too show what a flac file, through a decent DAC into a valve pre/ power combo and larger speakers can do (example only). It may not be for me, but the dealers should not fight shy of computer stored digital music, but should show what it can do given a chance.
sod the hi-fi, listen to the music