Despite what Patrick and Ian say, Singer is not going to announce something that isn't official.
Ian McKellen was just on a talk show yesterday where he said twitter is stupid and he doesn't tweet. That means it's his team that tweets from his official twitter handle, which you could have easily assumed because all of the tweets read like a publicist is tweeting it.
Anyway, before Singer sent his tweet, Ian's official twitter sent this out:
) shares secrets of upcoming projects (#JackTheGiantSlayer
). Welcome to Twitter, dear friend @BryanSinger
Now why would his team feel the need to tweet that at THAT specific time, an hour before Singer's announcement? Especially when Singer had already been on twitter for a month.
McKellen's twitter page then proceeded to RETWEET Singer's announcement. Yeah, sounds pretty off the cuff and jumping the gun to me...