When he said rewriting he was talking about Borenstein working on what Goyer did.From what Edwards replied to on his Monsters/ re-entry FB page he said they are rewriting the script and a 2nd quarter start date of principal photography in 2013.
Now someone else posted too that they had "sources in the industry" that said Legendary will not move forward on Godzilla until the see how Pacific Rim does which that would be a very bad idea for them to do because Pacific Rim could tank yet Godzilla could do very well because they are different and Godzilla is in a league of its own. Surely after the reception Godzilla got at Comic Con Legendary wouldnt screw this up by delaying it further?
If it is going to start filming in spring 2013 then we should definitely get an official teaser trailer next summer and a 2014 release date