The following are new Outlook 2010 integration features, which appear when Lync is present:
- New contact card with expanded options such as video call and desktop sharing
- Quick search from the Outlook Find a Contact field
- Reply with an instant message or call from the Outlook Home ribbon in the Mail, Calendar, Contacts, and Tasks folders
- Lync Contacts list in the Outlook To-Do Bar
Two additional Lync integration features are specific to Office 2010:
- File tab presence (click Info, and then look under Related People)
- Presence menu in Microsoft Office SharePoint Workspace 2010 (formerly Microsoft Office Groove 2007)
Source: Lync 2010 Integration on TechNet