I know for a fact that firefox usage is increasing very rapidly near me. Every fellow electronics employee at Staples is now using Firefox, and I stress the importance of Firefox to as many people as it would affect. I'm even getting fellow employees to spread it like i have the last 10 months.
Here at the university where I work, the tech support people have issued a directive to the oceanography department to cease and desist with use of Outlook, Outlook Express, and IE. Firefox and Thunderbird are the replacements of choice, and just about everyone has commented on how much nicer things run. My brother-in-law, who works at Dell, tells me that all the design engineers there use Firefox.
Firefox will have a hard time overcoming IE if it is not bundled with the computers that people buy. Some are just too lazy to go and download the browser. I write down the website for dozens of people a day (and the regular customers usually come back for other various things, and affirm that they are using (and love) firefox), but some are even adimately opposed to not using a microsoft product. that is what scares me.
My dad recently got a couple new computers, and he asked me to set them up for him. Well, IE and Outlook can no longer be found on them, and he has adapted to Firefox and Tbird surprisingly well, considering he is 65. I didn't even ask, I just did it!
(for those who are interested: Last Nov. there were few people who heard of firefox. around April/May, many have heard of it, and lately many say that they downloaded it, but just haven't used it yet. I encourage them to start using it. [this may explain the high download rate and lowering usershare])
I have had a Mozilla t-shirt for over a year now, and at the beginning, only computer geeks knew what it was - everybody else was like "Why do you have a red dinosaur on your shirt? And what is mozilla.org?" Now, people don't ask anymore - Mozilla and Firefox have become common names, at least among college kids.