According to it is several months late and it won't offer a lot of new features compared to version 1.5. A new feature is a spellchecker, which can be very handy when publishing a lot on the internet using a browser.
I am not too thrilled. Firefox is a fine browser. But how long will it take beforre all extensions work in 2.0 ? Is it worth switching as soon as it is released or should we wait ? I am still happy with 1.5. If it aint broken, don't fix it. But that's just me.