I was in the process of converting my maintenance plans over to regular SQL Server 2012 SSIS projects and I realized that SMO could make things simpler. It wasn’t totally clear to me how to set up the references, but this post explains it well. I hope it works!
By the way, the particular item I needed was the SQL Server installation path, so that I could locate the default backup directory. There are ways to get that from the registry, but I wanted to obtain it using the same SQL Server connection as that used by the SSIS maintenance tasks. SMO seems to be a simple way to do that, and it could be very handy for other maintenance functions as well.
Update (5/22/13): It turns out that I needed a different path — the one to the default backup directory, but that was also available using a different property of the same SMO object. My SSIS maintenance job is up and running now, and it has indeed made things simpler.