Because you can never have enough Rick Astley remixes. ;)
http://www.youtube.com/watch?v=Yl6SZzjG2ts
http://www.youtube.com/watch?v=2FP23SLTtKM
http://www.youtube.com/watch?v=Vqz6crf6xgc
In theory, you could segue from one mix to another on the closing credits, thus creating the ultimate rick roll...