The Mustang is a great car, with a rich and legendary history and in its current configuration is a very worthy competitor for the Camaro V6 or SS. I can't imagine it ever stopping production, but either way it deserves to live on. Things like this are cyclical - Ford WILL regain the upper hand in time, then lose it again, and so on.
At the risk of making us Camaro guys be the Joker, I'm reminded of his line to Batman from The Dark Knight: "Kill you? I don't want to kill you! What would I do without you?"