I agree with your points. Myspace is a wonderful bulletin board, but it’s not the solution. Artists pages, to my mind, entire netlabels featuring many artists, are the way to go.
The notion that many and perhaps most musicians will not be even semi-professionals but niche hobbyists also seems to me to be the future, and that this “sharing culture” will work more like a cadillac aficionado’s group for music makers and listeners than like little mini-a&r departments for the next big rock band in the sky.