I can only hope that the berry plots seen in one of the trailers are just a way of obtaining new berries, similar to the trees in X/Y. I just do not want a berry farm scattered across the region.
Hoenn's berry plots has always been scattered around the region, pretty sure they'll keep that.
But luckily for you, there are several berry plots right next to the Berry Master's house at Route 123. You can utilize that if you want a to farm a lot of berries in a single place.
...unless they change that, which appears to be the case if you look at the map. Let's hope it's a field expansion.