Migrate All Users From OCS Environment To Lync Server 2010 Pool With One PowerShell Command
If your organization is undertaking a migration from Microsoft Office Communications Server 2007 R2 to Lync Server 2010, at some point you will be tasked with migrating all existing user accounts (and assoc. contacts / groups) from one platform to another. Below is a PowerShell command (to be executed from the Lync Server Command Shell) that will query for all users hosted on the OCS platform and then move all returned results to the specified Lync Server pool.
Get-CSUser -OnOfficeCommunicationsServer | Move-CSLegacyUser -Target "lyncpool01.microsoft.com"