PeteNetLive - KB0000259 - Upgrade Exchange 2000 to Exchange 2003:
Now wait! - Public folder replication takes ages! Wait at least a week (I'm not joking) then check the replication status of all the public folders you added replicas for above, to make sure they are in sync. Also during this time your Outlook 2000/2003 clients have a chance to connect, and get updated with the new location of their mailbox before you kill the old Exchange server.
