Step 1: Replicating Exchange 2003 or 2007 PF’s to Exchange 2010
Add PF replica’s to an Exchange 2010 Server:
.\AddReplicaToPFRecursive.ps1 -server "Exchange 2003/2007 Server" -TopPublicFolder "\" -ServerToAdd "Exchange 2010 Server"
Replicate the System Folders to an Exchange 2010 Server:
.\AddReplicaToPFRecursive.ps1 -TopPublicFolder "\NON_IPM_Subtree" -ServerToAdd "exchange2010 server”
If you are planning to have multiple Exchange 2010 PF servers, you can repeat the Cmdlet
From the Exchange 2010 server: Update-PublicFolderHierarchy -Server "Exchange 2010 Server"
Step 2: Moving Exchange 2003/2007 PF’s to Exchange 2010
As a last step, after you confirmed that all the PF have been replicated to the Exchange 2010, you can move all replicas from Exchange 2003/2007 to Exchange 2010. The "move all replicas" will actually remove the Exchange 2003/2007 replicas.
To move all Exchange 2003/2007 replicas to Exchange 2010, which will actually remove the Exchange 2003/2007 replicas:
.\MoveAllReplicas.ps1 -Server "Exchange 2003 Server" -NewServer "Exchange 2010 Server"
Additional Cmdlets
To view a list of the replicas in the public folder hierarchy: Get-PublicFolder -recurse |fl name,replicas
For System Folders: Get-PublicFolder -recurse \non_ipm_subtree |fl name, replicas
To compare content replicated between the source and destination servers: Get-PublicFolderStatistics
Reference
Move Public Folder Content from One Public Folder Database to Another Public Folder Database – http://technet.microsoft.com/en-us/library/bb331970.aspx