It has been for the last three years, but Mozilla decided to go with Yahoo/Yandex/Baidu rather than renew the deal with Google. So Yahoo (and others) will replace Google as the main revenue source.
Have they disclosed the new financial terms of the agreement though? I'd be interested to see how the numbers have changed.
The numbers are never disclosed, but they can usually be inferred from Mozilla's public accounting. That'll take a while, though.
The only public numbers are from the the previous Google search deal (the one from 3 years ago). It will be a long time until the details of this new deal are public. In the mean time I (as a Mozilla employee) can say that all of the options Mozilla had for the new search deal were better economically than the now-ending Google deal. This was really nice, because Mozilla got to make a choice that wasn't about money, but was about strategy and what we want in the web instead.
Not any more. That's exactly what this story is about! :)
But the story mentions no $ numbers. Yahoo getting the default for US searches is clearly a big thing. Is that bigger than the rest-of-world searches? I really have no idea and seeing the figures would be very interesting.