From the Wall Street Journal, of course: http://online.wsj.com/news/articles/SB10001424052702303471004579163973063650890
I probably will regret having posted this, but well, I regret having read it. For my part, I think his argument suffers from the toxic combination of stringent rhetoric and zero sum logic. I also find the territory of his whole thought process to be muddled: mainstream, underground, young audience, older audience, so on and so on: none of it is so simple as he seems to think it is.
If Wynton is the voice of reason in your debate, there's trouble: "I don't think the art form [jazz] is going to receive anything by being R&B. That's already been done"