When I search Google for “grafana datasources”, the first hit is http://docs.grafana.org/datasources/overview/. It took me a while to realize that I am (probably) looking at some leftovers of an old version of the documentation. Could you remove that page or (better) make it a redirect to whatever is its current version? (I assume that’s http://docs.grafana.org/features/datasources/?)
Strange, there should be a redirect, thanks for informing us, will fix!