Star Wars was missing from the collaboration list of Fortnite. Mission accomplished from that night since Epic Games game have made official their brand new partnership by integrating the emblematic Imperial Stormtrooper in the shop of the day!
You can purchase this cosmetic for 1500 Vbucks. However, it only appears to be an "introduction" to a much wider collaboration. The leakers have already stated that the imperial ship is approaching Apollo Island. This is visible at the time of writing, even if it still remains at a significant distance.
Note that it is also possible to buy Star Wars Jedi: Fallen Order in the Epic Games Store to receive this skin directly on your Fortnite account.
We don't have more information on the whole event that might result from this collaboration. We can legitimately expect new weapons, changes on the map and perhaps new missions. Until then, may the force be with you!