The Devs are Responding, see link :

[Ãnna-silvermoon]

Also this:

Maximum Realm Capacity Increased – 28 August

With hotfixes that we are currently deploying to all WoW Classic realms, we are substantially increasing the number of players that can be simultaneously logged in and playing. We expect this to result in smaller queues for realms that have large queues, and some realms should no longer have queues at all. We will closely monitor performance and stability throughout this process. Thank you very much.