World of Warcraft will be releasing a new system called Connected Realms, that will allow players in low-population servers to play with each other without moving out from their home regions with two or more connected realms behaving as one server – with facility to join same guilds, using same Auction House, party up, and run the same raids and dungeons.
The feature is added with hope to allow players to participate in group activities without negatively impacts on other players sense of identity and character.
The feature is an advanced version of connected realms raiding and will be available on patch 5.4