From the Apple Website:
ProRAW gives you all the standard RAW information, along with the Apple image pipeline data. So you can get a head start on editing, with noise reduction and multiframe exposure adjustments already in place — and have more time to tweak color and white balance.
Any comments on what it might allow us to do once released?
I'm excited to see what it does for sure. I don't know any more than you do of course; my days of getting secret Apple info are long behind me ;-) But as long as it can be accessed by third party RAW decoders, and not just Apple Photos, I'll be happy to have it!
@PhotoJoseph— Have you signed up for the mailing list?