MCV is the new formulation of 20w50 motorcycle oil. They changed the formulation last year some time if I remember correctly. The AMV is still very good oil and is what I am still running, just the older formulation. I don't think they are still producing AMV just selling out the existing stock. I hope this helps.
MCV has a GL-1 rating which means it is like 75W-90 Gear lube, which is great for the tranny. It provides outstanding rust protection for the months your bike may sit in a garage in the winter months. Amsoil is always trying to improve their products and eventhough they had a good MC oil, they just made it better. For the past year I used Amsoil 20W-50 racing oil in my Ultra but last Oct I put in the new 20W-50 and I am happy with the results. Yes, I am an Amsoil dealer under George Douglas.