Firefox 2.0 is now available for download from this Index of page. Starting tomorrow firefox users should get automated downloads or reminders.
Personally, I’m going to hold off for a few days until I know that my favorite plugins have compatibility updates.
UPDATE: In her comment below, Cathy Gellis points out that the Mozilla folks are asking people not to download this version this way for good and interesting reasons.
You should read this page before downloading it. (The Mozilla people have asked that people wait until tomorrow.) Via Slashdot.