Really, why should I care about FF any more? They're killing us and themselves with all of these major version releases. As many others have pointed out, it's painful when dealing with web development, plugin usage, or even just to know what version is "latest". And that doesn't count all the pain with the major bugs that just languish while the UI is endlessly tweaked for no good reason (exactly why was the status bar removed?).
I'm sorry FF, but I'm sticking to the 3.6 series. As soon as that doesn't work anymore because of 1 OS upgrade too many, I'll stop using FF. If you can get things fixed and find sanity again before then, I'll stay. Otherwise, it's been a good 8 years we've had together.