Ben Yagoda talks punctuation in The New York Times:
If you're writing for publication, something else that comes into play is house style. This is seen most famously in the so-called Oxford comma - the one that goes after the second-to-last item in a series. Referring to the Philadelphia Phillies outfield as "Pence, Victorino and a left fielder-by-committee" would be fine in this newspaper but not in The New Yorker, which would change it to "Pence, Victorino, and a left fielder-by-committee."
All I knew before I read this, was that an Oxford comma was something that happened in a Vampire Weekend song.
I love punctuation. It's like the mathematics of words. At school, I kind of sucked at English so I never really picked up on the finalities of grammar and the like. I've had to figure it out myself which, as Yogoda points out, is really just common sense. Write it as you would say it. As it turns out though, my comma usage which does include the Oxford comma, has left me firmly in the "more deliberate and old-fashioned" department. Kind of like my usage of title case. Aside from writing as I'd say it - a function which happens naturally in my head - I attribute these quirks to certain publications that I read, or have read in the past: The Economist, The New Yorker, The New York Times (although I get the feeling from the article that the Oxford comma is not in their house style), and The Australian Financial Review which syndicates content from more business oriented journals alongside their own writers, aimed at the more top-hat, cigar smoking, chauffeur driven around in crowd. Yeah, it does scream of old world mentality.
To be honest, I've never really paid that much attention to the Oxford but I could be blamed for overuse of the humble pause machine that is the comma. What can I say, I like the little guy.
Even better: welcome to my house.