The tagline that both Lucasfilm and the U.S. Postal Service hope will entice you into signing up is "ON MARCH 28 TWO POWERFUL FORCES WILL UNITE", followed by the invitation to "BE THE FIRST ON PLANET EARTH TO KNOW WHY."
It seems pretty obvious, and not that creative, but what the heck - we're huge robot fans and we've been devoted to Star Wars since, well, "A long time ago, in a galaxy far, far away...." May 1977 in Southern California to be more precise. So we watched the new website teaser, entered our email, and will wait to see what havoc R2D2 and 3CPO can play with the U.S. mail system.
Update: According to the BBC (leave it to the Brits to let the cat out of the bag), the USPS is going to decorate 400 official mailboxes to resemble our favorite robot pal - R2D2. All we can say is that they better have 3CPO, or better yet, Chewbacca, standing guard.