Since there's no official promo material from the film so far, I figured we quench our thirst with some artwork from the people who are working on the film
Here are some Francisco Ruiz Velasco concept art for a non-related project, however it has Giant Fucking Robots™, so we get an idea of some of the designs for Rim.
I found this, what seems to be another teaser poster on Guy Davis' site
and some words from Davis himself
"Catching up on the website news after returning home from 11 months away working as part of Guillermo del Toro's core concept team on the upcoming PACIFIC RIM film! It was an amazing experience to be there from early concept and get to see it take shape into filming, and an honor to work alongside an incredible group of inspiring concept artists and friends. The film's not out until 2013, so there's not much I'm allowed to say or post for now, but will update more on it when I can."
Here's some Wayne Barlowe art