Several months ago, InStyle.com hosted a contest for several designers to come up with sketches for Bella's wedding dress. Christian Sibrian (from Project Runway) won the contest. It was not an official Summit contest so it was never confirmed that his design would make it to the big screen. (My favorite design was Monique Lhuillier's. You can see them all HERE.)
ET is now reporting that Zac Posen is the designer rumored to be in charge of Bella's dress. It's a very brief comment and, again, nothing has been confirmed by Summit. We'll keep you posted!