There are always some changes when Microsoft changes versions. This are slowly noticed by the Consultants and end-users.
Few below which I noticed:
· Colours of Business Process Flow Area on Forms have changed:
· Navigation changes for Security Area from Administration area for Teams, Security Roles, Users etc.:
CRM 2013: Navigate to Settings->Administration
CRM 2015: Navigate to Settings->Security
Note: Standard Administration functions are still under Administration Panel:
Hope it helps!