It shows as version Minefield 3.0a2pre.
The default page it is attempting to render after the upgrade is at http://www.mozilla.org/projects/firefox/3.0a2pre/whatsnew/
and was currently displaying a Mozilla 404: File Not Found page.
Does this mean that Firefox 3.0 Alpha 2 is just around the corner?
See the previous post about updates coming out today to versions Firefox 126.96.36.199, Firefox 188.8.131.52 and Thunderbird 184.108.40.206