This Slashdot comment sums up everything perfectly:

MySpace is not 'Web 2.0'. It's 'GeoCities 2.0' if anything.

A Little More

Web 2.0 is simply another name for the use of existing technology to do things that have already been done.  It is mostly a marketing term.  The focus for new and better web applications should not be technology, but functionality, specifically in terms of information architecture.  If it's shiny, but I cannot find what I want in a very short time, it is utterly useless and quite "Web -∞".