The newest versions of Exchange, SharePoint and Lync have many integrations between them. Use the links below to learn more and successfully implement them (based on my own personal experience):
High-Resolution Photos in SharePoint 2013 from Exchange 2013
SharePoint Site Mailboxes
Lync IM/Presence in Outlook Web Access
Create Lync Online Meetings in Outlook Web Access
Exchange Task Integration – SharePoint 2013 Tasks in Outlook
Adding Skype Contacts in Lync 2013
Using SharePoint eDiscovery to Search Lync Archived Messages
Using Microsoft Translation Services in Office Web Apps
Using Office Web Apps to Broadcast PowerPoint Presentations in Lync Online Meetings