Right in the feels :(
Long time online gamers know that Battle.net is as much a part of Blizzard as their back stories and lore.
However in this recent blue post, Blizzard have announced the decision to retire the Battle.net brand.
Some back story
In the old days of gaming, Online features were considered more of a novelty than a core part of the actual game. Therefore third party gaming services like GameSpy, MPlayer and TEN handled the interactive services, match-making and server directories. Battle.net added this extension - but in-house, controlled by Blizzard employees. Fast forward to the release of 'World of Warcraft' and Battle.net became as integral as the content itself.
Nowadays, online gaming is a given with any major title, and GameSpy et al are all long dead with Battle.net being the last man standing. A new generation of gamers have also appeared where the concept of a third party online service is totally alien, causing slight confusion between Blizzard and the Battle.net brand.
So what changes?
Literally just the name, the mechanics and features of Battle.net will remain the same after some re-branding and change of the name. Blizzard have already started the retirement of the name through releasing newer features like 'Blizzard Streaming' and 'Blizzard Voice' using their main name rather than Battle.net's.
The transition is expected to complete over the next several months.