All testing features starting from the professional edition
Test impact and MTM introduce great testing support for functional and no functional test that it should be available to all developers. The ultimate edition price reduce the opportunity for small/medium company to use this kind of functionalities.
Devin Ellingson commented
I could not agree more, asking a company to pay 6 times as much per-developer just to get unit testing related functionality is absurd.
If you don't want to make this functionality available to Professional users, then create another edition/price point that includes all testing functionality (including code coverage), or allow Visual Studio Premium to be sold w/o the MSDN subscription (like Professional) at a lower price point. (I'm not sure what Premium includes that is worth paying 6K, but I doubt it is the unit test functionality.)