You can check all the new features in the What’s New website, but for me best additions/improvements are:
- GetPasswordExpirationDate method that allows you to get the domain password expiration date for a specified mailbox user;
- The possibility to set automatic replies, such as Out of Office (OOF) messages;
- The possibility to expand a distribution list to display all members ;
- The possibility of getting user free/busy information.
For more information: