I'll throw in my predictions.
What I am pretty sure they will have:
1) Discussion / presentation of new solar panel solution (most likely a solar shingle type product).
What they might have:
2) Discussion / presentation of updated Powerwall with better stats, maybe an integrated inverter, and maybe slightly higher capacity. Direct charging of a Tesla car off of it for efficiency is a neat idea, but I would bet against it. Reason being, most people will probably only have 1 Powerwall, and it will probably be less than 10 kWh, and high efficiency charging for only 10% of the automotive battery capacity along with needing the Powerwall to be co-located with the parking spot probably wasn't initially worth the trouble for them to develop in the near term.
3) Discussion of updated Powerpack and maybe a gloss over of in progress Powerpack projects.
What I wish they would have, but probably wont:
4) A discussion of how and where the products will be sold, installed, and serviced.
5) Discussion of durability and warranty plans for the solar solution.
6) Assuming they go the solar shingle route, a discussion/overview of what roofing material is used for the rest of the roof where the solar is not installed (north facing roof, and possibly other shaded or low sun areas).
While I haven't been a huge fan of the solar shingle idea, I do give it credit for having the potential advantage of utilizing the entire roof area without the needed set backs that a traditional rooftop solar system requires.