http://www.pcgamer.com/overwatch-update/

The biggest slate of Overwatch balance changes in some time is now live, including reworks for the heroes Mercy and D.Va, as well as the new map Junkertown. 

First up is Mercy: Resurrect is no longer her ultimate ability; instead, Res is now a single-target ability with a 30-second cooldown. Her new ultimate, Valkyrie, enhances all of her abilities for 20 seconds. While Valkyrie is active, her healing and damage-boosting beams chain to other allies and have a much longer range; her blaster has infinite ammo and increased projectile speed; increased range and speed on Guardian Angel; Resurrect is reduced to a 10-second cooldown; and she can fly freely at increased movement speed. Here's what that looks like: