Exchange Server 2013 Service Pack 1 saw the return of the Edge Transport role, which was missing in the RTM release.
This article describes how to migrate your public folders from Exchange Server 2010 SP3 RU8 or Exchange 2007 SP3 RU15 to Microsoft Exchange Server 2013 CU7 or later within the same forest.
The serial migration, method described (below)to migrate public folders to the new Exchange, is being depreciated. The new solution is to use batch migration. Which should run considerably faster. It does have minimum requirements to your exchange versions though.