Currently there is no Web site that offers enough of an advantage over traditional methods.
There aren't any sites that have the "right people" reading them (a few have tried this, like iam.com [which folded last year] and
http://www.musician.com/mcom/).
Let's say I made a feature film. Why would I choose the Web over submitting to festivals and smaller studios? Sure I might make a site to promote it and offer downloads, but the gatekeepers don't visit those sites.
I think what's more important is that the cost of production is coming down. I can make films or record an album now without dishing out as much cash. That may get me noticed. Or once I've been noticed and have an audience/fanbase, I could do it Prince-style and use this stuff to be independent.
Above all else, anything that makes a lot of money for mostly white, privileged folk isn't going to change.