There are a couple major improvements in this release that many folks have been anticipating
Contacts & Organizations now has an interface for merging Contacts in the one-to-one model. There is a custom tab called Contact Merge that allows you to search for duplicate contacts and then merge up to 3 at a time. This is currently winner take all behavior—the non-winning Contacts will be deleted.
Contacts & Organizations now fully supports deleting Contacts in the one-to-one model via the API. This will clean up the process of mass deleting Contacts. One-to-one Accounts will be deleted automatically unless they have Opportunities associated with them.
Recurring Donations has some fixes to make it compatible with this new Contacts & Organizations package.