EDIT: Hal beat me to it. Let’s use his list, for obvious reasons.

Here’s everything I could think of that’s still in development/discussion for V2. Jump in if I’ve missed anything, and I’ll edit it into this comment:

Pasana Puppet Show (In development)
Potentially recoloring Ahch-To to go from nighttime to sunrise? (Discussion – I don’t think we decided one way or the other. I personally like the idea though. Plus, if the sky becomes purple at sunrise, it would symbolize Leia’s new lightsaber color.)
Finishing lightsaber crackle effects (In development – God bless the heroes working on this one)
Lightsabers fizzling out near the end of the Death Star battle, and after Palpatine’s defeat (In development, I think? I remember seeing a test clip, possibly done by MR?)
Maybe incorporating the Kylo on the Falcon deleted scene, if we can figure out a way to add the red cracks in the mask.

Things that have been finalized after a lot of discussion the last few dozen pages, and that we don’t need to bring up anymore:

Palpatine’s plan and the Snoke connection (Palpatine has been “Every voice” in Kylo’s head. Palpatine hasn’t “always” wanted Rey alive since birth; but he decides to use her as a vessel after Ben reforms.)
Poe used to be a spice runner
Rey and Kylo have “become” a Dyad - pending updates (basically implying that their connection has grown in strength since the last movie, rather than them being some arbitrary “Dyad” entity from birth)
And whatever else has already been incorporated into V2.