Here is the browser market share for October 2009, based on traffic to my top site:
Google Chrome: 7.40%
IE dipped below 50% for the first time since this study started, dropping 2.02% to 49.08%. Similar to September 2009, all other browsers gained at the expense of IE. Firefox (at 39.23%, almost to the 40% threshold) and Google Chrome (+0.76% to 7.4%) were particularly strong. Windows 7 release was Oct 22, and the data here appeared to show that it did not help IE’s fortune, as surmised here last month.