New
#10
It could be because FF decided to go with localized search engines. At least that's what I'm reading. US went with Yahoo, EU stayed with Google, Russia has Yandex.
You might have ended up with one of these: List of 34 Mexico search engines
Mozilla has it all screwed up. Users in the US were supposed to get the 34.0.5 update USLocal that has Yahoo as default, but my version is 34.0, there's supposed to be a 34.1 lurking out there somewhere.
From what I can understand Mozy wanted to revamp the search function for FF, wasn't sure how to do it, and ended up rushing the 34 update through. Don't be surprised if a v35 is in the very near future way before their normal release schedule.
Then there's the money angle: Yahoo and Mozilla Form Strategic Partnership | www.marketwatch.com
Related Links:
Firefox 34 / Possible to go back to the old search bar?
Don't Panic: Yahoo! is now default search in the U.S.
34.0.5 vs. 34.0