I suppose it's standard practice now -- I'm too cheap to buy a Chicago Manual of Style -- because this morning as I read the New York Times another example of the missing serial comma jumped out at me.
“Michelle was a very hard-working, intelligent and dedicated assistant,” he said. “I think she will be a very successful trainer.”
There's simply no need for this. Commas are as plentiful. And I doubt either production of the ink to print them or the voltage/amperage to display them add to global warming in a significant way.