By the way, I might as well add my reaction to the trailer/preview. Or at least, try to.
I'm not sure what to think, to be honest. The battle system is probably what I'm the most intrigued by, but at the moment I can't really see what the "hook" is. I haven't yet seen something that made me go "this makes me want to try out the new game!" beyond that neat battle system. What we've seen so far is basically Legends Arceus, confined to a city environment that doesn't appear to offer much variation beyond the colour of the rooftops and one big and impressive building for each of the five districts:
They released the official map in the website. I believe it shows the wild areas (where the Pokémon are fighting). Interestingly, I don't see diversity in the biomes. I'd expected a snowy and desertic biome, but they all seem to be just parks.
If this is it, I'll be quite disappointed. I mean, it is a big city for a Pokémon game, probably with many interesting nooks and crannies to explore, but is it enough to be a whole game world? Are we really
only going to travel through parks, back alleys, and rooftops? Will we be restricted to find new Pokémon in the canals and ponds of this one city? The strength of the Pokémon franchise has always been to, as the song puts it, "
travel across the land, searching far and wide". To explore the high mountains, wide seas and deep forests for new creatures. Not just rounding street corners until you find that one alley where wild Pancham live behind the garbage bin.
That being said, I hold on to hope that this is not everything. That our task is not to travel through the city and catch Pokémon, but to
bring Pokémon to the city. That, I think, is the Lumiose Urban Redevelopment Plan. Go out in the world, find Pokémon, give them a home in the city, and over time, you populate the city with Pokémon. I think that what we're seeing in Lumiose City isn't the areas where we go to find and catch Pokémon. It's a hub area that effectively serves as our living Pokédex.
One piece of evidence to support this impression is the fairly prominent gate structure we see in the lower right of the map, quoted above. That green building with the tower. It, and the first seconds of the trailer as seen in the Direct, suggests a gate used to travel to and from the city. While it is possible that the gate will only be used in the first cutscene where the player arrives in the city, I think we're meant to go through it a lot. Why else give it a tall tower, as one of only two interesting buildings on the city's outer ring? There's also the big dark building in the back, and possibly the train station (which was in the yellow section of the city in XY - could be that big building there), but it seems that this gate is the main way in and out.
So I keep my fingers crossed that they're keeping most of the game from us for now. Pretending that everything happens in Lumiose City only, then surprising us with a game filled with the beautiful biomes of Kalos. Of course, they will resemble the locations in XY approximately as well as those in Legends Arceus resembled DPPt, which is to say not at all, but I think it will be neat either way. Travelling across great natural landscapes to find the wild Pokémon that live in nature is a staple of the Pokémon franchise. It would disappoint me greatly if we were confined to the alleys and parks of one city.
Also, I look forward to seeing some of the new Pokémon and formes out there. Really hoping we get another equivalent to Ursaluna, Kingambit, or Annihilape, where a previously unremarkable Pokémon family receives a third member that changes my impression of the first stage from "a boring 'mon that will eventually become mediocre if I train it" to "a must-catch 'mon whose training will eventually reward me with awesomeness!" I do expect that most of the new Pokémon/formes will be Mega Evolutions, however. I'm fairly certain we'll see
something at any rate, because of the merchandise and marketing potential. They need recognizable 'mons to sell the game and continue the hype it creates.