Hi Simon
The 1.2.1 Enterprise version has been available for sometime. You should have received notice of this. There is a dedicated Alfresco server for customers and partners that contains the latest Enterprise downloads and other materials, for which your company should have an account.
The logic was that there are no bug fixes in the community release, as LDAP functionality was not in 1.2.0 Community.
Please get in contact if you need more detail.
Cheers
Paul.