Just about every developer I know has Firefox on their machine, but that's just because our automated tests tend to be written for Firefox. Almost none of the teams I have been a part of use Firefox for development, and even fewer for personal browsing. Chrome's market share grab has been quite impressive.

My most recent experience was with a client who was locked into IE for years, made the switch to Google Apps, and subsequently discovered the speed of Chrome. Phrased as "lots of our users skipped Firefox," it sounded like Firefox was in no-man's land.