the biggest issue for instruments i see in the future is no where near guitars actually.
as i've said a couple times before, my dad is a band director, and has been for 17 years. it used to be, grade school, you decide what you want to play, you go to the music shop(pe), you buy the instrument, you learn it and live it for the rest of your high school life at least, and then either give it up or go into it professionally. the quality of the instrument you bought your 5th grade year was good enough to get a good start on a professionaly career, and if nothing else, get you a decent head start in college.
now, even Walmart is selling band instruments. when they made guitars, i wasn't worried a bit. i knew that serious guitarists wouldn't be buying them up and playing them every weekend, and it was giving younger players a cheaper faster way to start. with the wind instruments, however, the local music shoppes (especially in my area) can no longer go out and service these instruments because they were so poorly put together in the first place, walmart replaces them for less than the repairs, and that has closed 3 of the 6 music stores in my area alone...
yes, kids are getting an earlier start, but they're not learning what it means to own a Bach Stradivarious trumpet or a King Nickel trombone. they can't take care of their instruments, and are laughed at if they ever show up to an even remotely semi-professional gig with them, discouraging them of ever playing anything in the future. so instead of being a one-time, life-long or close to it investment, playing a wind instrument or orchestral instrument now is becoming an amazingly expensive way of life, and in turn, a thing of the past. schools are closing their music and arts programs down, no longer supporting the creation of age old music, and everyone would rather suffer through modern day "pop" instead of a classical piece anyday. k, not everyone, but a lot of people, and at least 95% of the youth that 10 years ago would be picking up an instrument instead.
heck, even on guitar, no matter how much of a punk/classic rock fan i am, i can't appreciate the stuff today anywhere near as much as a timeless classical guitar piece from the early 1700's. alicia keys just doesn't cut it for me once i turn on Alfred Bredel's interpretation of Beethoven's 8th piano sonata.
ah, sorry, [/rant mode]