MSDN blog reports that the final version of IE 7 downloaded 100 Million times in last 3 months. IE 7 was launched 3 months back.
From the blog page:
I’m pleased to report that on January 8th, we had the 100 millionth IE7 installation. However, even more important than installations is usage. According to WebSideStory (the company we use to measure browser usage), as of this week, over 25% of all visitors to websites in the US were using IE7, making IE7 the second most used browser after IE6. We expect these numbers to continue to rise as we complete our final localized versions, scale up AU distribution, and with the consumer availability of Windows Vista on January 30, 2007.