Multi-hour long queues, just as you remembered them.
WoW Classic server queues

Blizzard launched World of Warcraft Classic today to some very eager rose-tinted glasses wearing fans today. The servers were live at around 6PM (ET) but you probably aren't even able to get in. About ten days ago, Blizzard had already warned players that some servers were already massively overpopulated. They estimated that login queues of over 10,000 players are a very real possibility if nobody made a switch to some of their lower population servers.

If you managed to get in, you may want to enjoy playing for as long as you can because you may not get back in if you log out. To those who are waiting in some of those queues: Good luck. I have already seen some people on Twitter showing off their queue times that are upwards of nine hours.

WoW Classic is available to everyone that has an active monthly subscription to World of Warcraft. That subscription grants you access to the current version of WoW along with WoW Classic. I'm sure a lot of old-school fans will probably try out Classic at some point, only to realize that maybe things aren't as great as they remember them being.