Seth has blogged his response to Walt Mossberg's interview with Mitchell and John, on top of the already great answer the two provided in the interview on
Why wouldn’t it just be better for the consumer to go with the company that’s hired experts to do its translations?
and here's my take.
The essential point to me is that we do get experts. We get experts in localizing Firefox. And we get experts we know. The people that spend their free time and passion to create Firefox in their language don't do it because they can lip sync Shakespeare into Portuguese, but because they share the values and mission that make Firefox Firefox. They care about the experience that people have with the web in their language.
The reason why our localizations rock is that our localizers know us, and we know them, and that we actually speak the same language.