So after todays's announcement I posted some thoughts on Z elsewhere, I figured I would share them here as well:
Pokemon Z will be a massive blowout! It's been worked on since the start of XY and they have had plenty of advances in it. The story will go bigger then before. We know flowers will play a key role in it. I believe all the mythical pokemon will unlock special things in game, and might even relate to the story. The ability to get Az's floette will probably come into play here. My bet is he ends up running out of immortality and dies peacefully, leaving his floette to the player.
I also wouldn't be surprised if there will be ties back to Kanto in this a well. I think that postgame we will go to Hoenn in an " Episode XYZ" in which the remaining plot lines between X, Y , and ORAS are wrapped up. Such as Looker, Ema, Zinnia and more.
All sealed off areas will lead to new areas in Kalos. I also think that volcanion will be important and get a primal.
As for when they announce it?
I predict that the game is announced before February 20th in a Nintendo Direct.
While that date?
Well in the U.S. XYZ the anime is airing way later then usual. There is usually a very short break between seasons. This one is over a month though. It airs the 20th. I think Z will be announced, with the U.S. anime being used to promote it here.
I also believe it will releasing either November or December. This is because that's when these distributions end. Things like the Jirachi distribution have started before the release of a 3rd game. This could be a similar scenario here.
Anyway that's the end of my thoughts on Pokemon Z.
In addition to this, I just learned about the super bowl commercial. I think it will be an advertisement about the 20th anniversary, but I believe they will mention Z, pokken, and go, and show things to get people hyped about them,