I don't think the lack of Python 3 support was reflective of a value judgment about Python 3, so much as that most of the companies willing to fund PyPy development so far are still on Python 2, and were more interested in funding other kinds of work (performance, numpy, cpython extension compatibility, etc.)
> I also sincerely hope that this portends Firefox bundling a Python runtime with the browser, providing a DOM API, and letting sites provide client-side scripts in Python. JavaScript has been allowed to reign for much too long.
This strikes me as extremely unlikely. There's zero appetite for introducing non-standard language runtimes into browsers these days as far as I can tell. But I guess you never know.