It's a bumper night for Overwatch at BlizzCon 2017 - there's both a new hero and a new map coming!
The new hero is Moira, a support healer. She can teleport - an ability called Fade - and she produces beams and orbs that heal and drain. Her ultimate looks like a combined super-beam that heals all allies caught in it, or drains all enemies.
The new map is Blizzard World, a zany theme park map based on all of Blizzard's properties. It's a hybrid Assault and Payload map and it's going live early next year, and will be on the PTR very soon.
In addition, Blizzard aired a new animated short for Reinhardt, which was wonderful as they always are.