Blizzard says that it will actually "need queues to properly stress test our services" so people may need to wait a bit before getting in to play in the Diablo IV open beta when it starts Friday.
Diablo iv open beta known issues. RSS
After pushing out some "backend server hotfixes" Blizzard says beta testers for Diablo IV should see much shorter waiting times to play the game. The early access open beta ends on Monday
The start of the Diablo IV early access open beta today has been hit with lots of issues as the game's servers have been slammed with tons of people trying to play the action-RPG sequel.