The browsers used by visitors to any site will vary according to the intended audience for a site, and how well that site supports the browser.
One techie site of mine --
http://www.rebol.org -- servers nearly 45% of its pages to Firefox users (that excludes pages served to bots of course).
That's on the high side for a general audience. But, as the site should render well in most browers later than Netscape Navigator 4, it is an indication of which browsers are currently prefered by a high tech audience.
Personally, I don't care much. Browser choice should be the users' choice. It's just my role when acting as a webmaster to not do anything that trips up any browser.
