I've finally found out what the issue was with my MS-Test harness, and why I am the only one currently seeing this issue in my office.
First I needed to turn on logging for MS-Test. Here's a link on how to do that.
Then, once I ran my tests, and looked in the log, I saw the following error message:
The Visual Studio performance and coverage logging engine is already running on the computer. Therefore, the test run cannot continue. Close the pending performance or code coverage session and then rerun the tests.
Here's a link to the fix
I'm the only one in the office having this problem, because I am the only one with VS2008 Team System Team Suite and running code coverage and analysis.
I also suspect that I'm the only one who's pounding out all the test code they need to be writing right now, but that's going to change. Soon.