I have just noticed that there is a Wikipedia entry on the use of "they" as a singular pronoun. It is an interesting entry and worth reading. I still can't stand people using "they" as a singular pronoun in writing, but it seems that almost everyone is using it that way in speaking. And it is becoming more acceptable in writing too. In the textbook I am using for my Introduction to Philosophy class, I find the following sentence:
Suppose that someone is a good, kind, nice-tempered person and then has a car accident and spends the last year of their life with a changed personality.
"They" refers to the "someone". What can I say?