I have a little bit more information for you on this.
I have figured out this this only occurs if I have code coverage enabled through the .runsettings file. If I disable code coverage through that file then I can run the tests through visual studio without a problem.
With Code Coverage enabled, I have tried linking Typemock to the Visual Studio 2012 profilers and I get different types of errors such as this
------ Run test started ------
The server did not provide a meaningful reply; this might be caused by a contract mismatch, a premature session shutdown or an internal server error.
========== Run test finished: 0 run (0:02:19.0139) ==========
and I get a pop up window from vstest.discoveryengine.exe indicating that it has stopped working.
If I try to run the test through the TypeMock runner with profiler linking then then test runner hangs.
Please let me know if there is any additional information I can provide.