I'm with boobybird. If you don't like it, buy the girl ones. All the regular diapers are unisex. By the time a toddler is wearing pull ups, they can pretty well decide if they want Dora or Cars. Its pretty much one of the first choices they get to make.
When you're that young, things are simple. Only us adults try to complicate things like gender.
If I have a daughter and she points to a barbie, woohoo, her life is going to be a lot easier. If she points to GI Joe, whatever, she gets a GI Joe.
Hell, when I was that young I had barbie and Ken. I turned out to be a fairly stereotypical male.