A new set of forums have been created specially for 1.5.
http://forum.joomla.org/index.php/board,428.0.html General Questions
http://forum.joomla.org/index.php/board,429.0.html Installation
http://forum.joomla.org/index.php/board,430.0.html Migrating and upgrading
http://forum.joomla.org/index.php/board,432.0.html Security
http://forum.joomla.org/index.php/board,431.0.html Administration
http://forum.joomla.org/index.php/board,433.0.html Performance
Keep a close eye on news from Compass, we have 3 great templates that we are preparing for 1.5, and two of them are free!