Darth Vader Big Bad of Rogue One?

As always this is to be taken with a grain of salt but Birth Movies Death is reporting that Darth Vader might appear in Star Wars Anthology: Rogue One. The movie will be a prequel to 1977's Star Wars Episode IV A New Hope by showing how the plans for the first Star Wars were stolen and I assume made their way to Princess Leia's hands for the iconic opening of that movie. Darth Vader's role is described as "[Vader] will not be the main antagonist but he will be working behind the scenes, pulling strings and will appear onscreen. Literally, I'm told - he'll be showing up via viewscreen or holo projection or something." Considering the "time" of the film's setting, a cameo appearance of the character does make sense. As usual time will tell on rumors like this.