In the coming months, we're planning an update to Battle.net that will
give you more control over your online presence when playing Blizzard
games. Soon, World of Warcraft, StarCraft II, and Diablo III players
will be able to select "Appear Offline" as one of their Battle.net
social-status options (along with Available, Busy, and Away) for those
times when they want to wander Azeroth by their lonesome, dominate the
galaxy in radio silence, or slay demons in solitude. When you choose
this option as your status, all of your Real ID friends, BattleTag
friends, and character-level friends will see you as “Offline” in their
friends list whenever you’re logged into a game.
The “Appear Offline” status option will be added to World of Warcraft,
StarCraft II, and Diablo III separately in future updates for each game.
For Diablo III, we expect to add the feature in a patch after 1.0.5.
For World of Warcraft and StarCraft II, we expect to add the option
sometime after the release of each game’s upcoming expansion.
Thanks for your continued feedback, and we’ll share more information on
the availability of this new feature in the months ahead.