While I still maintain that they ruined Mercy (and are continuing to do so, especially with the constant nerfs), Blizzard seems to have heard the plea of support mains around the world in one respect: "We need more support!"
And thus, Moira enters the Overwatch lineup.
She basically looks like a wizard, so that's an immediate point in her favor. She has a history with Blackwatch and currently works for Talon (like a certain wraith-person we all know and love) as a geneticist. Ability-wise, here's what she can do according to the official Overwatch site:
BIOTIC GRASP: Using her left hand, Moira expends biotic energy to heal allies in front of her. Her right hand fires a long-range beam weapon that saps enemies’ health, healing Moira and replenishing her biotic energy.
