Nothing new from the trailer (at least info wise). However I don't know why people keep saying Bewear/Lucario has a Signature Z-Move. The reason the look different is because we were only seeing a part of the Z-Move animation and put together we see what the full Fighting-type Z-Move looks like.
Also, don't remember whether it was here or not where Z-Move Power discussion took place, but now that we know the Z-Move's Power is based on the Power of the move it replaced (do we have any idea if that follows a formula or did they go through each move and assign it a Z-Move power?) I don't think status moves will suffice for attacking Z-Moves.
Also I was thinking how Rayquaza would solve its issue with having a Mega Evolution button and Z-Move button at he same time: it won't. Maybe if Rayquaza know Dragon Ascent the game will simply not allow it to hold a Z-Crystal (coming up with some BS like how the power emitting from Rayquaza is nullifying/repelling the Z-Crystal). Yeah, a bit of a cop out since Mega Rayquaza can hold other items, but it would solve the issue and go with the idea that Z-Moves is essentially Mega Evolution energy focused into one super attack, you can have only one but not both.