Almost all players have run into the very annoying issue where you can not enter an instance due to the servers being full. Blizzard has now announced that this should be greatly reduced in North America, as Crygil from Blizzard announced.
As mentioned in previous updates, we have been working diligently to address recent instance capacity issues through a number of reconfigurations and optimizations. These modifications have been an ongoing effort, and weÂre pleased to announce that the process is now complete on all North American realms. Since the optimizations, all realms have shown an improvement in instance performance as well as a noticeable reduction in the amount of players hitting the instance limit. Please be assured that we will continue to monitor the situation closely and will make further changes as necessary. As always, thank you for your patience and understanding regarding this issue.