Been a while since I've seen a comment thread containing so much gibberish... Apparently Mozilla releasing an entirely new product is going to make Firefox slower, or change its UI (which you can already do yourself JHFC are people still whining about FF4?), or it's going to spontaneously generate ads that don't exist, or something....
Personally I'm really interested in seeing what this is. From my perspective Firefox has always been the browser to develop in, given that it has the most consistent rendering engine and the best toolsets for developers, so a developers-only version sounds right up my street. If they did split them and remove the dev tools from standard FF entirely, would that actually speed anything up? Aside from the fact that every other browser long since stole Firebug's developer panel, most of the dev tools are turned off during normal running anyway.