This is an interesting paper about
pronoun use among Japanese children, how it's changing, and the increasing use of 'boku' by girls and the social reaction to it. It does have a few brain-breaky phrases near the beginning (like 'hegemonic linguistic construction,' which... I keep feeling like that refers to something that would seem really self-evident to us if it weren't in aca-speak). But if you can get past that, it's a pretty interesting read.
I think the thing that surprised us the most is that 'ore' is now apparently being used by boys as young as 6 or 7. Though I think my favorite part was the mother who said 'well, if the boys are all using "ore," why don't the girls take over "boku"?' An entire school of bokukko-- it's kind of an awesome thought, actually. XD