It had already semi leaked before today, but Blizzard has just announced Overwatch Retribution which will include a brand new PvE mission (and a new map for PvP).
The PvE mission will feature McCree, Reaper, Genji and Moira and take place in a new map set in Venice, Italy.
A variation of the map will also be available in the PvP Payload mode of the game. Obviously, there will be a bunch of new loot for you to grab as well when the new mode launches on April 10th (lasting until April 30th).
You can watch the epic promo trailer below.