From what I can gather, it seems that at the Nuremberg Toy Fair (which starts tomorrow in Germany) there are Rogue One: A Star Wars Story costumes on display. Twitter user @DarenArsenal1 has snapped some pics of the costumes that look to be legit. Check them out:
https://twitter.com/darrenarsenal1/status/691992264244121600
https://twitter.com/darrenarsenal1/status/691992500677009408
https://twitter.com/darrenarsenal1/status/691992672614088704
https://twitter.com/darrenarsenal1/status/691992782823657472
Knowing nothing about these characters, their costumes sure do look cool. Hopefully we get to find out more about Rogue One in the coming weeks!