Back in December 2011, the Exchange team first started making the Exchange Online December 2011 Service Update available to customers. This rollout was staggered globally, with full deployment expected to be completed within six months. For more information on the new features and enhancements included as part of this update, please refer to the original blog post.
While we are pleased to announce that most Office 365 tenants have already received the Exchange Online December 2011 Service Update, there are still some regions that are awaiting this update. Full deployment to these remaining tenants is expected to be completed over the next six months. Approximately one week before the service update is deployed to these regions we will post more information in the Planned Maintenance section in the Service Health Dashboard panel. Administrators should check this resource for awareness of when their update is scheduled to begin.
Thanks very much for your continued patience and support as we finish deploying this important update to the service.
Exchange Online Team