Why is it so much easier to find cute girl nursery ideas than it is for boy nurseries?!

Anyway, I think we want to do a navy nursery with vintage baseball touches. I am almost 100% that we are going to go with this bedding from Pottery Barn Kids:

http://www.potterybarnkids.com/room/rom/rombnr/romnurnvyenv/

I think I want to do a complimenting rug in the nursery too. The nursery is carpeted though (cream colored), is it weird to put a rug on top of carpet?

Any ideas of cute patterns or alternate colors to compliment this bedding?