D23 has thrown up a lot of really interesting things, from concept art of Doctor Strange to some trailer action. Perhaps the most interesting was the addition of Hannibal Lecter himself, Mads Mikkelsen to Rogue One's cast.
Mads is known for his quality acting, so it's a coup in itself for the Star Wars spin-off to get him, but who is he playing? While not confirmed, there is one major character from the original trilogy canon who he could very well be.
Rogue One is the tale of the Bothan spies who stole the Death Star plans, that helped the Rebels destroy the original Death Star.
While not directly referenced in the original films, there is one character who appears in Return Of The Jedi who was directly involved in the theft. Indeed someone who turned his back on the Empire to join the rebellion.
General Crix Madine
Madine is an Imperial Officer who decided to defect when he realised the danger the Death Star would pose and is arguably the main reason the data finally ends up in the hands of the Alliance.
In terms of appearance, Mads is very close to the original character and he would be able to portray Madine as a genuinely torn man, his loyalty to the Emperor being matched against his conscience. As he has just finished the role of Hannibal, it is also a chance for Mads to play a good guy for a change.
Of course this may not be the case, he may play a different character entirely, but as soon as I read his name, I saw General Madine in my head.
With some of the other cast announced like Alan Tudyk, this could become a really strong movie with the right pacing.