This is probably the best casting decision Hunger Games producers have made since hiring Jennifer Lawrence to portray Katniss Everdeen. According to Slashfilm, Julianne Moore has officially signed on to portray President Alma Coin in the third and fourth films of the Hunger Games franchise—specifically, the two-part adaptation of Mockingjay.
This casting has been rumored for a while, and though it seemed pretty likely back when the news broke a couple of months ago, it's nice to have some confirmation. If you're not familiar, Alma Coin is a huge part of Mockingjay: She's the president of District 13, who is described as a "manipulative politician who figures brightly in the finale" as Katniss becomes a "symbol of rebellion against the autocratic Capitol government." Basically, she really messes shit up for Katniss.
With Moore's casting locked down, Mockingjay is set to begin filming soon—the first installment is due to hit theaters in a little over a year, on November 21, 2014, and the second installment, which will film next year, will hit theaters on November 20, 2015.