I can't answer your question for Visual Studio 2008, but I know that Netbeans has a few integrated tools for you to use.
- The code coverage two allows for you to see which paths have been checked, and how much of the code is actually covered by the unit tests.
- It has the support for the unit tests built in.
As far as quality of tests I'm borrowing a bit from the "Pragmatic Unit Testing in Java with JUnit" by Andrew Hunt and David Thomas:
Unit testing should check for BICEP:
Boundary, Inverse relationships, Cross-checking, Error conditions, and Performance.
Also quality of the tests are determined by A-TRIP:
Automatic, Thorough, Repeatable, Independent, and Professional.