Film Metro appears to be hosting preview screenings of WALL•E on the 23rd and 24th of this month in Portland, Seattle, Denver, San Francisco, Santa Clara and Sacramento.
Currently it seems as if you can sign up to be alerted when the tickets are able to be reserved on June 16/17.
Thanks to rachelcakes1985 at the Pixar Planet Forums.
YAAAAAAAAA-Wait, only 3 days ahead? You call that a preview?