Mozilla has just flipped the switch on the new, rather beautiful Firefox 4 download page. You can keep track of Firefox 4 downloads around the globe with Glow, a beautiful pseudo-real-time download counter. There's also Twitter Party, which builds a Firefox logo mosaic from Firefox-related tweets.
Firefox 4 Officially Launched
Along with the download page, there is a lovely HTML5ified tour of Firefox 4's new features, covering Sync, hardware acceleration, the new privacy controls, and links to the Web O' Wonder demos, how to set up Panorama, and more.
Mozilla has set up a pseudo-real-time counter!