There are some links I found what gleaning that bit of information. Most of this was not obtained from the MS site. With them there is no discussion of managed versus unmanaged, because in their world no unmanaged code exists :-)
MSDN download page for VS 2010: http://msdn.microsoft.com/en-us/vstudio/bb984878.aspx
This is the MSDN link for a trail download of Test Professional: http://www.microsoft.com/downloads/details.aspx?FamilyID=2d96b979-f9fd-4728-bc6b-2f8b82777829&displaylang=en
Although this has nothing to do with unmanaged code, here is an example of using MSTest and NUnit together: http://alsagile.com/archive/2010/03/09/stop-the-war-between-nunit-and-mstest-make-them.aspx
What's new for testing: http://msdn.microsoft.com/en-us/library/bb385901(VS.100).aspx
A discussion where MSTest is not recommended for unmanaged code and GTest is: http://stackoverflow.com/questions/1392305/mstest-for-huge-legacy-codebase
And example of calling MSTest from the command line for several test projects: http://stackoverflow.com/questions/3236268/mstest-msbuild-many-test-projects
MSTest command-line options: http://msdn.microsoft.com/en-us/library/ms182489.aspx
Testing the application: http://msdn.microsoft.com/en-us/library/ms182409.aspx
TestToolsTask: http://msdn.microsoft.com/en-us/library/aa721750.aspx
Gallio, third party software for testing: http://www.gallio.org/
Testing working in IDE but not from command line: http://coderesource.org/messages-7-286282-c++-mstest_for_huge_legacy_codebase
