You're thinking of the Global handle. It allows people to add that name instead of everyone one of your character names, that way they'll always see you online no matter which character (new or old) you've made. It also has some chat features, but it's nothing like this.

no no Keifu.

The global name @name has been in CoH.

What they are now doing, is making all character names unquie to that global name.

So, in CoH, my global is @shooshoo. I want to make a fire/fire balster name Flame Dude. Well, the global name @eatveggies already has that name, I can't use it, and will have to think of something else or a variation Flam3 Dood or w/e.

In CO, we can BOTH have the name Flame Dude, b/c it'd be Flame Dude@shooshoo and Flame Dude@eatveggies. So, they're opening up the nameing policy so that you're never limited by what names other players (current or unsubbed) used.