The first surprise at the Rogue One panel was Gwendoline Christie hosting. The second was the poster, and the third is the behind the scenes clip we see above.
John Knoll revealed that he first came up with the idea of a the story when he first heard rumblings of the live-action series, during the filming of Revenge of the Sith. He put it away when he learned more about George’s concept for the series, and pulled it out again when the spinoffs were announced. Check out the original concept art of the team.
Edwards also confirmed that the beach planet is named Scarif, and later cast revealed another planet, Jedha. Apparently people make Force-based pilgrimages there – Edwards compared it to Mecca. This appears to be the market planet, and where we meet Chirrut Imwe (Donnie Yen,) Baze Malbus (Jiang Wen) and Bodhi Rook (Riz Ahmed.) Edwards had more to say on Jedha in a post-panel interview – it’s certainly an intriguing addition to the galaxy.