This isn't the most important news, but....
Horde battles aren't restricted to wild Pokémon.
It seems that the villains have actually gotten smarter, and finally started ganging up on players.
'Horde battles' appear not only as wild battles, but can be trainer battles as well!
-Translated from the official Pokémon site.
Pokemaster seems to be fairly active, but I thought I would post this anyway because it doesn't seem to be on the US site.