This article by Katarzyna Puchala and Matt Stehle provides information about how Exchange ActiveSync selects the protocol version to communicate with Exchange Server.

Find out what's new in the 1.2 release of the EWS Managed API. The EWS Managed API SDK includes new conceptual and reference material to help you develop client applications that use EWS.
November 7, 2011

This article by Jason Johnston explores the provisioning process from the perspective of an Exchange ActiveSync developer.
October 27, 2011

The Active Directory Schema Changes Reference has been updated to include additional changes that Exchange 2010 SP2 makes to the Active Directory schema.
October 19, 2011