Near as I can tell, the pet shop is gender neutral, and the "Lego Friends" sets don't appear particularly gendered:
http://shop.lego.com/en-US/Pet-Shop-10218
http://shop.lego.com/en-US/LEGO-Friends-Mias-Skateboard?icmp...
Similarly, Farnsworth House (http://shop.lego.com/en-US/Farnsworth-House-21009), the 4x4 crawler (http://technic.lego.com/en-us/Products/default.aspx#9398) and mindstorms (http://mindstorms.lego.com/en-us/products/default.aspx).
The fundamental difference between Friends and the rest of lego seems to be that Friends is about people, whereas the rest of lego is about building stuff.