[bloak]

I think there's strong evidence for weak forms of the hypothesis. For example, the available colour names in a language affects the way people classify colours as measured by the way they perform a task in which language is not used. See Guy Deutscher's "Through the language glass" for an overview of this and many other fun things.

There's also the whole business of how propagandists twist language around in order to influence people. How is that not an example of language affecting people's world view?