How will React 0.14’s Stateless Components offer performance improvements without shouldComponentUpdate?

This question has been going round and round in my head since I read the release notes (and other related hype) around React 0.14 – I’m a big fan of React and I think that stateless components ( are an excellent idea, both for the ease of writing such components and for expressing in code the intention that these components should be “pure” in terms of rendering consistently for the same props data.