Haha, Riv LOVES pink, it's his fave colour by far. I suppose it depends on your view re: nature vs nurture. I do believe that girls and guys have some differences, like guys tend to be stronger (my dh is less active than me and heaps stronger), and girls make the babies. So, the anatomical differences.
And I suspect we're even wired a bit differently when it comes to how we interpret the world, how we communicate and stuff.

But you're right, people do place these expectations on our kids. What I'm going to try to do is give my boys (and girls if I ever have any) the opportunity to make their choices based on their interests, not societies expectations. If my son takes a liking to a doll or pink clothing, well, why not? And if someone tells them they can't do something because of their gender, I'll defend my kid's right to pursue their interests.

Okay...I might have rambled, I'm watching Rove at the same time...sorry. :P