I saw Google wave demonstration video the Google staff was using Firefox in Googles official presentation. Even they used to said "let we open firefox" "opening firefox" Does it mean that they dont believe in their own Chrome Capability???
I do believe that Firefox built the engine behind Chrome. They both work together anyway. Firefox's homepage is Google. Google does not tell users to get Chrome when using Firefox, but if you visit the Google homepage with IE it recommends they get Chrome.