Historically, one of the best parts of Blizzard’s various single-player games has been building custom maps; it worked out well for Warcraft III, clearly, and people have long enjoyed producing what amounts to entirely different games in other titles. The Workshop in Overwatch isn’t going to have quite that much power (at least to start with), but it is going to allow you some pretty creative map styles by allowing you to set up custom scripts that can force people into mirrored matches, turn the floor into lava, or otherwise produce a wildly different map style as you play the game.
It’s currently only up on the game’s test server, but the possibilities for what you can do in the game, for hero abilities, and for the game as a whole are already powerful. You can make for a wildly different game experience, recreate other classic games, or even create whole new experiences from the ground up. Unfortunately, the scripts currently only get stored for six months, but let’s see what monstrosities players develop and what happens through testing. It should be interesting, that’s for sure.