http://www.cbsnews.com/stories/2008/10/24/tech/cnettechnews/main4542817.shtml
Supposed to be even faster than Chrome.
Yep, I installed it a few days ago for web development because of a bug in Firefox 3.0 which disabled the Response tab of files under the Net panel of Firebug. I don't really feel any difference while using it though (maybe because Firebug is slowing it down), and for web surfing, I'll probably be either sticking to Chrome or jumping back to Opera 9.6.
If I install it, will it interfere with Firefox 3 which is currently installed on my computer?
It may cause some of your add-ons not to work as it conducts an add-on update on first run, which may install a newer version of an add-on you're using that is incompatible with the older version of Firefox.