Visual Studio has deprecated test lists. It has been replaced with Test Categories. Currently there is no way to put a Test Studio test into a test category. As a result, when using VS 2012 or 2013, or a TFS build definition in TFS 2012/2013, you cannot specify which tests to run. You can't specify a test list, only a test category, but Test Studio tests cannot be put into a category. You're stuck.