Thank you for this. I had no idea saving space was the reason the 's was dropped or the serial comma. The serial comma thing seriously bugs me (even though I drop it on occasion as well) because it is just not correct. It isn't. I don't care who says it is acceptable - it isn't.

You should do a whole post of who/whom.

Oh, and the incorrect plurality verb tense agreements used in "Spin" and "Rolling Stone."