Joel Semeniuk's Blog
Is it possible to create a Microsoft Management Console Snap-In with .NET? I know about the MMC Snap-in Designer for Visual Basic – but don’t know if there is anything newer or pre-canned for the .NET world.
Not sure if this is what you're looking for: http://sourceforge.net/projects/mmclibrary/
Here are a couple more: http://www.codeproject.com/csharp/MMCFileActCs.asp http://www.thecodeproject.com/csharp/SnapIn.asp
From my quests on the net, I found that Microsoft declares it as possible, but not recommended. I have personally created an MMC clone, purely in .NET, to avoid problems.