After Joomla 1.5 Beta 2 came out on May 2007, I became an everyday (at most) at the Joomla Forums. In that forum, I reported some concerns while testing the Joomla! beta 2.
Right now, as the beta testing progresses, I no longer found anything to be reported. Everything as far as I am concerned, Joomla! Beta 2 is working perfectly. Beside, almost every concerned I had has already been fixed.