In Exchange 2007, public folder replication works basically the same way it always has. The troubleshooting steps in the first three parts of the series all still apply. However, the admin tools have changed and the common problems we see with Exchange 2007 are a little different, so that's what I want to cover here.
Changes in the Admin Tools — The event log is still your best tool for narrowing down a replication problem to a particular point of failure. In Part 1, I suggested turning up logging on Replication Incoming and Replication Outgoing to Maximum. That still applies, except that with Exchange 2007 you'll be using the Set-EventLogLevel cmdlet to set "MSExchangeIS\9001 Public\Replication Incoming Messages" and "MSExchangeIS\9001 Public\Replication Outgoing Messages" to the Expert level.
In Part 2, I described how to use the Synchronize Hierarchy and Synchronize Content options in ESM to force a status message and to timeout all outstanding backfill entries. You can still do this in Exchange 2007 via the Update-PublicFolderHierarchy and Update-PublicFolder cmdlets. These are also available in Sp1's public folder management tool, appearing as Update Hierarchy when the Public Folders root is selected and Update Content when a particular public folder is selected. Because you can use these from the command line, they are a lot more flexible than the Exchange 2003 options. For instance, it's now very simple to time out backfill entries for every folder that has a replica on your Exchange 2007 server with a simple "Get-PublicFolderStatistics | Update-PublicFolder" command. That wasn't possible in Exchange 2003 without a lot of clicking.
In Part 3, I described how to use the Public Folder Instances view to see if the deletion of a replica has completed. In Exchange 2007, you use the Get-PublicFolderStatistics command to see that same information.