With Microsoft Fakes moving to the Premium SKU of Visual Studio in 2012.2 (CTP4 is now available) more people will be looking at using them.
I have just installed CTP4 and have seen a behaviour I don’t think I have not seen in the previous version of Visual Studio (I need to check because as well as CTP4 I have recently installed the new version of Typemock Isolator 7.3.0 that addresses issues with Windows 8 and Visual Studio 2012).
Anyway the error you see when you run a fakes based test is ‘UnitTestIsolation instrumentation failed to initialialize, Please restart Visual Studio and rerun this test’
The solution is to disable Typemock Isolator (Menu Typemock > Suspend Mocking), when this is done, without a reboot, the Fakes based test run.
Does mean you can’t have a solution using both Fakes and Isolator, but why would you?