I have to admit I missed this update when it came out. In some Office 365 training in TVP last week we mentioned that it was now supported to install DirSync onto a DC. Well here is the info….
Version 6567.0018 released on 22/11/13 provides support for installing DirSync onto a DC. See the change log HERE - and keep checking there for version updates.
See this link for information on the ‘Windows Azure Active Directory Sync Tool’ – and specially note that there are specific instructions required for installing on a DC