Gehennas server discord: https://discord.gg/jjPpZc
It was created 45 minutes ago, we're around 800 people in it for now, it's probably gonna grow to thousands the next days
NB: some context: Gehennas is the new English pvp realm, since shazzrah and golemagg would have been way, way too populated on their own. It's quite possible that we'll see new realms appear before and after the launch as well, as Blizzard mentioned 'and extremely important' demand.