I have a daughter and so far she has 3 princess sets, and 4 friends sets. I dont think the girls sets will be overproduced. I think there are many girls who will love those sets and I predict good growth in that area for Lego.
The Lego Movie has helped the company grow more in sales. I mean the entire movie was like a gigantic commercial for Lego haha.
I bought the Dragon Mountain set when it was on sale for $30, and my daughter took the dragon right off the bat and she loves that thing haha.