There were some premature announcements around the blogosphere the last couple of days, but Firefox 2 has now been officially released. It is primarily a user interface upgrade. Some of the changes include a built-in inline spell checker, a built-in phishing site detector originally developed by Google, automatic session restoration in the event of a crash, a search engine manager, new icons and tab styles, and other odds and ends.
You can download Firefox 2 from the Mozilla website. Firefox 2 will be rolled out as an automatic update for Firefox 1.x users within the next few days.