Following a leak which suggested Overwatch would receive some sort of Christmas/holiday-themed update, Blizzard all but announced the event today.

In a tweet this afternoon, Blizzard said "You’re invited!" along with the animated gif below. It shows a snow-capped version of the map King’s Row, suggesting part of the update will include modified versions of existing maps. This is accompanied by the date December 13, which is apparently when the update will go live.

It seems safe to assume part of this event will also include themed loot boxes and new items, as was the case during the Halloween and Olympics updates.

Data miners discovered the existence of a Christmas jingle in the game’s files recently, pointing to a new event. Blizzard has not been shy about the fact that it plans to offer more of these events, so a Christmas one comes as no surprise.

Source: GameSpot