Yes, Devel::Cover is one of my favorite new toys too. I just actually showed it to my boss to demonstrate exactly what you are saying, how we can test test-coverage. He was really impressed, it was one more thing to help me in selling this way of testing.

Do you happen to have a link to that TPJ article? I actually read about this module on CPAN (saw it in the CPAN nodelet one day and was intrigued), but i would love to read the article.