I am sure rumour controllersTwilight Lexicon will have something on this soon.... but IMDB is like WIKIpedia... it can be edited by its users, which means anyone with an account can plug in any information they wish.... regardless of its truth.
If a movie hasn't started filming yet, it seems to me IMPOSSIBLE to set a release date. I could be wrong, but I think this is simply a guess based on "basic" film making math.
Wednesday, April 28, 2010
Don't Believe everything you read - Breaking Dawn Release Date
IMDB has listed a Breaking Dawn release date of November 3, 2011.