I see Deepend weren’t the only ones excited about the upgrade!

From Mashable:

Firefox 4 has been downloaded more than 5 million times in less than 24 hours since it became available, according to Mozilla’s official download stats page.

Currently, the counter shows 5,755,000 downloads, most of which originated from Europe (2.5 million), followed by North America (1.6 million) and Asia (1 million).

In comparison, Microsoft’s Internet Explorer 9 was downloaded 2.35 million times in its first 24 hours of availability.

The final version of Firefox 4 brings full CSS3 and HTML5 support, a redesigned UI, App Tabs, syncing accross multiple devices and Panorama, a feature that lets you organize tabs into groups using a drag and drop interface.