Yet another university - Sonomo State University in California - is reportedly going to begin offering a virus writing class. What's the purpose of such a class? Well, supposedly to help teach people how to better defend their networks.
How many people need to know how to write a virus in order to defend against them? I don't know of any administrators that have the time to worry about the inner workings of a virus to the point of being able to actually write one. Instead they worry mainly about keeping them from doing damage. Adequate virus behavior descriptions from antivirus software makers typically gives an administrator enough knowledge to take defensive actions.
McAfee's Karthik Raman wrote a little bit about the ethic consideration of classes. You can read Raman's opinion over at McAfee Avert Labs Blog.