The trailer showed a town, and you can see most of the town, or at least what looks like most. I can't see a mart, but the Pokémon Center has Blue things on the roof, which would suggest Marts are still in the PC.
I've no problem with this, just the towns seem to be empty without to resourceful buildings, It's a general tradition in RPGs to have a building for healing and a separate one for shopping, unless it's an important or final area, like a Colosseum of the League.
I'd like a shop for elemental stone, with new Pokemon being made, they'll most likely without a doubt need stones, and new ones. I don't like how the newer games limit you on the stones you get with only finding them in caves and dungeons, and various one place findings, there's more pokemon that need to evolve with them, than the amount you can find.