Chrome was the world's most used browser on March 16th

"It may only have been for a single day, but according to StatCounter Google Chrome finally managed to surpass Internet Explorer to become the world’s most used web browser.
On Sunday, March 16th, Chrome temporarily slid ahead of IE with a share of just over 32%. Weekends have historically seen a downturn in IE usage. As people wind up their work week and spend more time on their home computers, they’re more likely to use an alternative browser. IE still maintains a dominant position in corporate environments, but that too has begun to change.
Over the past year, Chrome has steadily climbed while IE continues to fall. Initially folks thought that Google’s rapid rise was being fueled by Firefox defections, but Mozilla has only seen a drop of about 5% — while IE is down more than 10%. A second chart from StatCounter tells the story: those IE peaks and plateaus are clearly on a downward trend.
It’s important to note that StatCounter doesn’t correct its usage figures to account for one detail that could skew the numbers slightly in Google’s favor. Speculative pre-rendering (which arrived  in the Omnibox in Chrome 17) and Instant Pages support (which appeared in Chrome 13) both cause Chrome to send additional traffic to web servers that may never result in an actual visit from a user."

Source:  Geek.com, 22nd March 2012