Now boys, can't we all just get along.
The fact is that template has been around long before Go Media put it in their product. Just go to shirt.woot.com. They have had it at least a year to offer it to designers to mock up shirts for their contests.
And Gomedia already has a tutorial out on mocking up shirts:
How to Create Awesome T-Shirt Mockups Like Jimiyo|GoMediaZine . They also have a video.