UPDATE – November 23rd – a new version has been released. The version is 1.0.6567.0018
UPDATE – November 12th – this version and reference associated has been removed. Many issues have been introduced, such as filtering not applied or corruption in display name (not everyone has been impacted anyway)
Recently – in fact yesterday, November 4th, Microsoft has released a new version of the Directory Synchronization tool which now can be installed on domain controller. 
You can download it from http://go.microsoft.com/fwlink/?LinkID=278924
Procedure for installation on domain controller is here http://social.technet.microsoft.com/wiki/contents/articles/17370.best-practices-for-deploying-and-managing-the-windows-azure-active-directory-sync-tool.aspx#A11