According to Deprecated Features in SQL Server Replication - New Items Deprecated in SQL Server 2012:
The RMO API is deprecated. Build new applications using Transact-SQL instead.
For those of you who use the Replication Management Objects (RMO) API to program the various replication agents or use RMO/Powershell to configure replication topologies, I have created a Microsoft Connect Suggestion Item to reconsider the deprecation of the RMO API:
http://connect.microsoft.com/SQLServer/feedback/details/774485/rmo-api-deprecated-in-sql-server-2012
If you would like the deprecation of the RMO API to be reconsidered, please vote the item as important. Thank you.