Based on the cluster that was the name reservation event, there’s certainly cause for concern. Additionally, the most recent stress test touted increased server lag and newbie zone s&#@ shows with mob sniping and variable respawn rates.
I too think that there will be a major drop off of Classic players within just a couple of weeks but the way it looks currently - Blizz is not prepared.
Put this thread in the bank. Launch will be a cluster to rival TBC launch.