As announced over the summer, Microsoft was targeting an end-of-year release for Exchange Server 2010 SP2. True to their word, Exchange 2010 SP2 was released earlier this week. As with all updates and service packs, previously released update rollups are included in SP2.
As expected, new features include a basic text-based mini-OWA, suitable for low bandwidth and low resolution mobile devices. Like the old WAP version of OWA, if offers users bare-bones access to their mailbox. Another OWA enhancement is cross-site silent redirection for OWA. This provides users with a single sign-on experience with Forms-Based Authentication or when the client access server needs to redirect an OWA request to a CAS in another Active Directory site.
Organizations will be able to use address book polices to segment their address books into smaller subsets of users. Administrators will be able to bypass the "legal hold" feature in Exchange 2010 that prevents users from deleting anything from their mailbox.
For those sites slowly migrating to Office 365, a hybrid configuration wizard makes it easier to deploy a mixed site, where some mailboxes are local and some are hosted on Office 365.
Download Microsoft Exchange Server 2010 Service Pack 2 (SP2)
Read more about it:What's New in Exchange 2010 SP2 (TechNet)