I just got back from NerdCon: Stories in Minneapolis and had a great time. Hank Green and Patrick Rothfuss started NerdCon last year. It was in Minneapolis--not sure if it will be next year, presuming they do it again. (Ticket sales were apparently down a little.)
In addition to being a great time--lots of silliness, including a panel that included a guy in a squid costume, and John Scalzi in a lip sync contest--there were serious panels on craft with people like Daniel Jose Older, Nalo Hopkinson, M.T. Anderson, John Green and the like.
NerdCon: Stories isn't specifically for kidlit, but the attendees are overwhelmingly in their teens and twenties. It's eye opening to hear them talk about favorite podcasts and games and such. It would be worth the price of admission just to sit among them and jot down dialogue.