Ubuntu's Firefox maintainer has stated that Firefox 3 Release Canidate 1 will be released in Ubuntu Hardy.
I don't understand where all this assuming and misinformation is coming from but yes, RC1 will be done soon. (I have confirmed with our FF maintainer, Alexander Sack)

(Definitely not today, as most of the ubuntu-mozillateam is in sessions at the Ubuntu Developer Summit, please be patient.)
http://ubuntuforums.org/showpost.php?p=4993809&postcount=61