That would be great as one of the things that puts me off of front end development is lack of language choice. I adore Python as a language and it would certainly make a great choice for a front end language if supported. Maybe if this project takes off, browser vendors would ship a Python interpreter alongside the JS one. I'd bet that Apple, Google, Mozilla, etc. could make Python fast if they threw as much money at it as they do their JS interpreters. And PyPy is already pretty fast -- it's certainly way faster than JS engines were before V8 and JavaScriptCore hit the market.
This will probably never happen, but I can dream.