I know it can be risky putting a chat channel in for the entire world so everyone can post on it no matter where they are, and all messages will be seen as it opens up flamewar possibilities etc in chat. However of all the games I have played that have local chat the game seems totally dead. You feel like you are the only one in the world.

My main MMO is Everquest 2. There's the infamous level 1-9 chat on my server where all manner of randomness is posted but the game always seems full no matter which forgotten corner of Norrath you are stuck in. Its also fun when you are crafting to chat on there. I really miss this kind of chat on a lot of more modern MMO's.

It would keep the community together as well if there were cross server chat options so players in the Xbox and PS4 worlds can talk to the PC world and vice versa. EQ2 also had this.

with this megaserver thing they talk about im not realy a fan of a worldwide chat, since we can be talking about millions of players in a worldchat, i rather see zonechats and a tradechat