It's not the TV series - the animated serires is set during the Clone Wars and the live action one is still a few years away (this "event" is slated for next year). That's artwork for the videogame. You can check it out (and three more pieces)
here. As you can see, it looks like a game set during the Dark Times.
Why they're calling a game "the biggest entertainment event of the year" and "a major addition to the Star Wars mythos" is beyond me. Two guesses:
1. It's a Shadows of the Empire type multimedia event (i.e., game, novel, comic series, soundtrack, etc.)
2. Lucas himself is working on the story. (Not that farfetched - LucasArts recently announced that their upcoming Indiana Jones game features a story "written for the first time under the direction of George Lucas".)