Bug 343825, "Enable official branding and set version to Firefox 2 Beta 1 for upcoming release", was recently checked in to the 1.8.1 branch. This can only be good news, and a sign that the first beta build of 2.0 is on the verge of being released. Perusing through the change logs over at The Burning Edge, as well as the nightly build notices in the Firefox Builds forum at MozillaZine, yields some cool new features and fixes. The ability to undo closing a tab has recently been added, although you should be forewarned of bug 343801, which causes the history menu to intermittently disappear. Also, passwords are now auto-filled before all images are loaded. This is a great bug fix; no more eBay login trouble!
I am really excited about Firefox 2.0, and when the first beta is officially released, I'll certainly switch over. The nightly builds have been getting more and more stable, and they're certainly a joy to use. Thankfully, release day is only getting closer.