I would say Chrome is doing some pretty innovative stuff with V8 (and open sourcing it to spawn amazing things like NodeJS) as well as Native Client & VP8/WebM.

I use Firefox for development because of Firebug

I use FF for casual browsing because of Adblock plus

The plugins make the browsing experience for me

Yes the same here, Firefox is my main development machine and chrome is secondary.

I wish a world where firefox+chrome+open source derivatives have >80% usage share globally.

I don't subscribe to the dogma about tools. You should use what ever gets the job done. I personally use Firefox for debugging (I love FireBug). I use Safari for general browsing, mostly because of the integration of Bookmarks and Reading Lists over iCloud. And I dabble in Chrome when I'm using a non-apple machine. I think all tools are good and bad, and picking one side just limits your options for productivity. My 2 cents.