From the Wikipedia page on Mozilla Foundation:

The foundation has an ongoing deal with Google to make Google search the default in the Firefox browser search bar and hence send it search referrals; a Firefox themed Google search site has also been made the default home page of Firefox. A footnote in Mozilla's 2006 financial report states "Mozilla has a contract with a search engine provider for royalties. The contract originally expired in November 2006 but was renewed for two years and expires in November 2008. Approximately 85% of Mozilla’s revenue for 2006 was derived from this contract."; this equates to approximately US$56.8 million.

What!!! No way!
That means Google is basically keeping Mozilla afloat. WHY? Is Google going to buy Mozilla?

Very startling fact. This paired with Google's latest scandals, of censorship in China, makes me wonder whether I should trust Mozilla has good intentions.