Permission Set Groups is a new feature that allows Admins to combine multiple permission sets into a single Permission Set Group for user assignment.

The Salesforce Known Issues site lists issues based on the number of customer reports, the severity of the issue, and the availability of a workaround. 

You can now use the External Account Hierarchy to share records owned by the users of child account with users of the parent account. 

The Clone with Related action clones objects along with their related records, hence the original object’s related records are also added to the cloned one.

How to report on objects and fields defined in Salesforce? You can now create a report from custom report type based on Entity Definition & ...

You don't need to create custom fields every time to capture information, instead, #Hashtag records in Salesforce with a feature called ‘Topics’.

Use Delegated Administration in your Salesforce Org to grant a group of users the privileges to create/manage users within their own department.

Social Accounts, Contacts, and Leads is a productivity feature to link these records to their respective Twitter handles to follow from within Salesforce.