About a month ago, Firefox Creative Lead Aza Raskin revealed "Tab Candy", a Firefox feature designed to make managing tabs easier. It shows an overview of all tabs so they can be quickly located. It also includes other organizational features like tab groups.
It has only been available in alpha form, but Raskin announced today that the feature is coming to Firefox 4, and starting today it will be known as Firefox Panorama, rather than Tab Candy.
"While there are many directions still left to explore (some of which are covered in the Tab Candy announcement video), there is a strong set of design principle that have and will continue to guide development," says Raskin. "We’ve already see[n] activity from extension authors to extend the capabilities of Panorama, which makes now a perfect time to discuss Panorama’s design principles."