We have just heard from a reliable source that the shooting of Game of Thrones season 3 is to commence soon, namely on July 9th. The prepping for the shoot has started and will take place over the next two weeks.
Hear Me Roar: Sounds legit. This means they are starting some two weeks earlier compared to last year. In addition, if that is the case, then casting announcements should really be here any day now.
Update: Extras NI has begun booking extras for season three. More proof that filming is imminent.