I wouldn't hesitate to diaper a boy with a purple diaper. I am however trying to wrap my head around using the flowers and butterflies prints on a boy. I'm more than OK with putting a little girl in robots and airplanes but I can't really see myself doing the opposite with a boy. I feel so sexist. :S
I'm the same. When I learned DS's gender I was glad to plan for a boy b/c I felt like I could put a girl in boy stuff but not the other way around. Weird.