I posed the same question to Course Manager support not long ago and this is the reply I received:
I understand that you are asking if it is possible to view your private course using a Mac or PC. I'm happy to answer that for you.
If you were to make a publicly available Collection on iTunes U, students could download or view many course materials such as lectures and podcasts. But to maximize the full functionality of a course, such as subscribing, reading posts, and viewing assignments, the iTunes U app on an iOS device is currently a requirement.
I'm not personally aware if Apple is working on making courses compatible with computers, but if you would like to submit a request on behalf of your institution to have this functionality added to iTunes U, you can do so at the following link:
iTunes Customer Feedback portal
Feedback from customers like yourself is largely responsible for our continued success. This is particularly so with new services, since provers like yourself are among the first to use the service. Any effort to inform our team about ideas and enhancement requests is sincerely appreciated.
On the form, in the "I Have Feedback About:" drop down menu, please be sure to select "an enhancement request" to ensure your comments are routed to the team responsible for these kinds of decisions.
Not the answer I was hoping for...