If SOA and AJAX is the Killer App, Who is it Killing?

I'm seeing this more and more, the idea that the browser becomes not just the interface from some middleware powered app that orchestrates the services, but that the browser, by means of Ajax, becomes the orchestrator of services, cutting out the middleman. I see this trend in the stated desire of Tibco to have it's GI product drive the demand for services in the enterprise. It is a trend that worries me.