WordPress 3.5 is now available. You can ship it in few weeks.
One can also post the problem related to the release in its support forum sites like: http://wordpress.org/support/forum/alphabeta/. Moreover developers can also test their plugins, themes etc to check the compatibility issues, that will be fixed before final release.
To test wordpress 3.5 you can try plugin from the following link http://wordpress.org/extend/plugins/wordpress-beta-tester/
Else can download the candidate file from http://wordpress.org/extend/plugins/wordpress-beta-tester/.