Lets all take a deep breath.
That was a huge bombshell. A StevenBomb, if you will.
For those of you who ignored the SPOILERS warning, you decided to continue reading this so don't blame me for this:
Rose Quartz is Pink Diamond
As of A Single Pale Rose my last theory was proven.
But this raises many questions, and as you saw in the title, mine explores Jasper. I wanted Jasper to be redeemed as much as anyone, because her story, though she was ruthless, was very sad.
That being said, I think this development spells out a redemption ark. Specifically Jasper's. I know she has been corrupted, but if Steven can find a way to heal her, she could see Pearl's memory, see that Pink Diamond is Steven, and, maybe, just maybe, get a redemption.
(This is just a theory, so please don't rip me apart. I am just as flawed as you.)