As far as selling out... My best example of what you guys are talking
about is U2... Their music has change a lot over the years.  I very
closely followed them early on and for several years. Even saw them 7
times on the Joshua Tree Tour.  But beginning with Achtung Baby, their
style of music began to change too much for me.  I was never bitter or
angry or anything; I simply saw it for what it was -- that they were
growing as a band and moving in a natural direction for them.
Interestingly, "All that you leave behind" is very much like some of
their earlyish stuff (not too early, but unforgettable fire era early)
and I've been listening to that a lot lately.