Blizzard has decided to do away with the name Battle.net and simply call the platform Blizzard. It was a bit old fashioned.
Blizzard said, "When we created Battle.net, the idea of including a tailored online-gaming service together with your game was more of a novel concept, so we put a lot of focus on explaining what the service was and how it worked, including giving it a distinct name.
"Over time, though, we've seen that there's been occasional confusion and inefficiencies related to having two separate identities under which everything falls - Blizzard and Battle.net. Given that built-in multiplayer support is a well-understood concept and more of a normal expectation these days, there isn't as much of a need to maintain a separate identity for what is essentially our networking technology."
Only the name will change - indeed, has changed. If you load what was the Battle.net launcher on your computer you will now see it is the Blizzard launcher. The indistinct swirly logo has been replaced by the Blizzard logo.
Battle.net launched in 1996, back when Britain was a part of Europe. It launched to enable multiplayer in fighty fantasy game Diablo, and was popular because it was built directly into game, was free, and was easy to use. It provided Blizzard games with a solid online multiplayer platform for years to come.
But 20 years later "Battle.net" sounds a bit naff, a bit 'I play games in my bedroom'. Plus, who in their right mind would stick with a brand ending '.net'?