Hey,
Till VS 2010, only tests that are part of Test project would be listed in Test View. This is a limitation that has been fixed in
Vs 2011.
To answer you question : One work around to get tests from non-test projects listed in VS is discussed
here. Note that it is not a Microsoft recommended way. You shall use it at your own discretion.
On a related note, if you are not aware of it, even in VS 2010, running tests from MSTEST.exe command line works fine for non test type projects too.