I have been reading about this. It was pretty abrupt. Apparently tried Nikon one day and sold everything the next day. He did have a falling out with Canon so I don't think we will ever know if that was the reason or he decided he just didn't get enough keepers at the end of his day.
I did learn and appreciate his offerings. There is always Grant Atkinson for Canon info and tutorials. He has a lot of videos out on youtube. His work at his site is impressive.