I told you back in June 2012 that James Cameron would make three “Avatar” sequels, turning the whole thing into a four parter. Someone announced it today. But readers of this column knew about it 14 months ago. http://www.showbiz411.com/2012/06/26/james-cameron-will-film-three-avatar-sequels-at-the-same-time. I told you he’d shoot them at the same time. This is why Sigourney Weaver couldn’t do more “Political Animals.” And it’s why she’s left “Vanya and Sonia…” on Broadway early, ceding her role to Julie White. The time has come to make the films. So just in case you read this all now as “exclusives” you can say, Hah! I knew about it a long time ago.