I don't think liking role playing and action fantasy/ sci-fi is a learned behavior for girls, so there.
My sisters and I often played make believe when we were little. My youngest sister was always a gypsy girl, my other sister was a runaway princess, and I was a reformed assassin (I had all the cool fighting/killing skills without the moral issues that way, I guess) who owned an inn that was always used as the base of operations.
I think the first movie my mom took me to was a Star Wars movie, though.
I think it just helps to have both parents like gaming and speculative fiction. Brenna's been inundated with such things since birth, after all. She's been to three movies in the theater--the newest Harry Potter, Chronicles of Narnia, and King Kong. Her favorite toy to chew on is a little green plush dragon with a rattle inside.
One of her favorite activities is actually sitting on Chris's lap as he plays World of Warcraft. She likes when he jumps or kills monsters.
Granted, she's not even four months old yet, so she may turn into a sparkly princess type yet, but I was always more interested in fighting bad guys when I was little...
Oh, and I liked your article. 'Twas a fun read! Good luck on bringing your children over to the geeky side.