Lync Server 2010 has a delegation feature that enables users the ability to enable delegation to other Lync users to recieve and make calls on another person behalf. Now you can go and make someone a delegate by going to
Call Forward settings
Edit my delegate members
Clicking add, and then adding the people you want (you can not add federated users as delegates)
Now the interesting piece is that Lync delegation can leverage Exchange delegates. So this means Lync 2010 can leverage your existing delegation settings from either Inbox and or Calander settings.
Now the issue I ran into before was a user asked me a few questions:
Question: How did the delegates for Lync just appear there?
Answer: If a end user has users delegated in Outlook in either their Inbox or Calender then those delegates are going to appear in Lync automatically.
Question: Does that mean that the people in my Lync delegate will recieve my phone calls on my behalf?
Answer: Not necessarily, you will have to go into Lync (see above) and select a user with a check box?
Question: So why is it that when I go to try to remove some people from my Lync delegation area that just keep coming back?
Answer: Well, in Outlook you can give people different levels of access. For those users that you give “Editor” permissions in your calender, you are giving those users the ability to schedule meetings on your behalf. So just because you remove them from Lync as a delegate they are going to reappear.
Question: How do I get those users in my Lync delegation to not come back?
Answer: By editing those users permissions in your Oulook calender from Editor to Reviewer you should be able to remove them from Lync (see above) and those users will not reappear anymore.
Hopefully this is helpful information going forward.
Byron Spurlock's Teams, Skype, & Exchange Tidbits 