Andrew Sullivan has an entry about "s/he," or, really, the singular "they" with a collegial link that I'll gladly take as an invitation to weigh in on the subject: 

Man (emoticon goes here), do writers and copy editors wish the singular "they" were standard! It's not, yet, but here's why it would be handy if it were: Write "he" about a nonspecific person and you're a sexist. Write "she" and you're a flaming feminist. Write "he or she" and you're a pedant. Write "they" and you're an ignoramus. 

We word people can't do much about the political implications of phrasing, so we're left to consider what makes a person look or sound pedantic, prissy, inattentive, lazy, stupid, or ignorant. In the case of the singular pronoun, the version about which it's likeliest that standards will change -- and the version about which we can do the most to change them -- is  "they." I'm doing my bit right now.

Apparently, the singular "they" is more nearly standard here in the U.K.: This morning, without even trying, I spotted one in "The Sunday Telegraph," which was delivered to my room along with breakfast. The silly thing is that it was in an all-female context, like "Every mother ... they." Of all places where a generic pronoun is pointless!