Although the 200 million download mark doesn't translate into that number of users -- some have downloaded multiple versions, others canceled the download, still others downloaded but don't regularly use Firefox -- Mozilla's has acquired about 15 percent of the global usage share in the nearly 21 months since it was released. In the same time span, Microsoft's Internet Explorer saw its share drop from the high 90s to just under 80 percent.
That also doesn't take into consideration the businesses that use Firefox, often installing it on dozens of machines but downloading it only once. Overall, this is encouraging to fans as well as the developers. We all hope that Firefox 2 will not dissapoint.