This is a ways off, but the LEGO KidsFest is coming back to the Austin Convention Center September 4-6.
http://www.legokidsfest.com/austin/
They'll have life-sized models of Darth Vader, Batman and others, along with a huge map of the United States covered with LEGO skyscrapers that people can build and contribute to. They also had a full sized Lightning McQueen model from the Cars movie. And of course they'll sell LEGO sets there.
We went a couple of years ago. It's a must for any LEGO nut like me or people with kids.