Rod Howarth asked a very pertinent question on RvtMgdDbg:
Question: Just wondering, is the 2010 version allowed to be distributed to non ADN members? Is it uploaded anywhere? I would have thought it would be ok given the 2009 version and its source code are publicly available. Just thought I'd check.
Answer: Thank you for asking this very pertinent question. As said in the discussion on RvtMgdDbg for Revit 2009, this is an essential tool that we recommend to every Revit developer, so obviously it is important that everyone who needs it has access to it. The Revit 2010 version of RvtMgdDbg is included in our Revit API webcast training material which can be downloaded from the public ADN API training schedule site > Revit API, or using the following direct link. For completeness sake, here is also an alternative download site for ADN members.
Late addendum: It is now much, much later, March 2011, and for yet more completeness' sake, here is the complete source code, Visual Studio solution, and a compiled assembly DLL of RvtMgdDbg for Revit 2010, prompted by the comment by Sangsen on MEP connector direction and the CreateAirHandler SDK sample:
As hinted at by Sangsen, RvtMgdDbg was renamed to RevitLookup and included in the official Revit SDK in the Revit 2011 cycle.