Well... Fuck. That was an episode and a half. So Salem got humanity noah'ed but in a much more efficient manner and I would have to agree with what someone said that Dust is all that is left of those humans.
I'm positive Jaune is the descendant of Salem and Ozpin.
This also makes it clear that it IS possible to bring a person back to life, just not that it is looked favorably upon by the gods. It is obviously going to play into the story and does give Jaune a reason to maybe go to the dark side but I actually doubt it. The Brother of light said that 'life and death are a delicate balance', my guess is that Jaune will try and trade his life so that Pyrrha can come back because it would fit his character. He sees her death as his fault because he was too weak and that the world is better of with Pyrrha and not him (something a lot of Jaune haters will cheer about if it comes into play.)
So one prediction is that Jaune will be confirmed as the descendant of Salem and Ozma. Salem will try and twist Jaune to her side promising Pyrrha brought back to life. on if he turns to her side I am split so I can't really make a call. However, at some point the brother's WILL be summoned back and Jaune will play a pretty big role in humanities fate (Suck it haters) and will ask the brother's to bring Pyrrha back but to keep the balance will offer his life instead. Then, something really mushy, corny, and tropey will happen like Salem realising her errors and for the life of her descendants and their happiness will offer her life instead.
Now this seems the obvious path so I will also postulate that the writers will go "NOPE, SUCK IT FUCKERS, NO HAPPILY EVER AFTER PYRRHA DOESN'T COME BACK. DOESN'T THAT MAKE US EDGY AND COOL?! DOESN'T IT?!"
Given that RWBY is basically a modern fairytale either ending is pretty likely. The reason being that old school fables were DARK AS FUCK so I wouldn't put it past the writers to try and emulate those darker stories that usually had a dark and/or bittersweet ending. That being said, more modern spins on those older tales have a much happier ending which is now an accepted way to write a story hence "happily ever after." So really this lore bomb basically turns the ending of RWBY into a bit of a binary chance of 'dark' or 'happy' ending.
Honestly I WANT the happily ever after because I fucking hate bittersweet or unhappy endings, mostly due to my nihilistic and pessimistic outlook on life where a story is literally sometimes the only way I find even a fraction of a moment of 'happiness' in my otherwise depressed and fucking bleak life where all things end up being shit. So BECAUSE of my fucking sucky and shit life where the world seems to reveal in my continued suffering and drowning me in endless depression the writers will choose to go "DURRRRRRR, BITTERSWEET ENDS R KEWL AND MAKE US EDGY, PYRRHA STAYS DEAD!"
Now if the writers don't go with either of those routes and actually give us a third option I will be legitimately impressed but given their past track record it doesn't look good since they fucking fridged Pyrrha in the first place to get us to this.