Released: Exchange Server 2010 SP2

@Schema Change???: Yes, there's a schema change, as mentioned in the announcement:

http://blogs.technet.com/b/exchange/archive/2011/05/17/announcing-exchange-2010-service-pack-2.aspx

Announcing Exchange 2010 SP2.

In order to support these newly added features, there will be a requirement for customers to update their Active Directory schema. We’ve heard the feedback loud and clear from our customers on multiple occasions regarding delays

that can be caused to deployment as a result of needing to update your schema and as such with the release of Exchange 2010 SP2 are communicating the required changes ahead of release in order to assist our customers with planning their upgrade path ahead

of time.

Additionally, you can find schema update details in http://msdn.microsoft.com/en-us/library/dd877014(EXCHG.140).aspx

Exchange Server Changes to the Active Directory Schema, which outlines schema changes from Exchange 2003 through Exchange 2010 SP2.