@CStaffa: An improper usage could be appropriate in a title if the author is using the title to parody improper usage. Perhaps capitalization wouldn't matter in that case, but I always like my "bad English" to stand out against an otherwise correct construction.

Overall, I agree with gssilver. There are plenty of instances in which Chicago, MLA. and APA do not correspond, i.e. whether or not to include the comma before "and" preceding the last item of a list.