I still think the second reveal will not be until September-ish 2017
and expect to see beyond what we know for sure:
HUD (I've been convinced of this since 3/31, so would be pretty surprised if it's something else)
swoop the dash toward the display to conceal the bracket (as was done between the X prototype and final)
at least 2 battery choices (I know, I went way out there with that one)
fewer interior options than the S/X (would guess a light and dark dash color, the dark fabric and a light and dark leather (or gag vinyl))
not too spaceship-like wheel (I don't want to constantly explain to passengers how a spaceship works)
at least one new paint color (one can hope, and I hope if there is one, it's not matte black)
two wheel sizes, but not going to guess if they will keep with the center mount
the updated 'signature' tesla nose
an updated iPhone (android) app (I've not used it, but according to the app store reviews, it REALLY needs it)
I am sure there are a dozen other things I've convinced myself the final version would have, but this is what comes to mine