Spoilers!
Random thought: I remember back when Blizzard said they needed to nerf overlord drops in order to make Protoss openers other than stargate viable...and since then, stargate -> phoenix -> oracle -> *insert any of a handful of builds that will kill Zerg if they respond improperly and can't be scouted now that phoenixes have killed their overlords* has become
more entrenched as the standard opener in every single PvZ