There's a reason why the servers are going to be down for ~12 hours--the servers are moving to a new data center, and the server data is moving with them.
I'm fairly aware of migration times and why it can take 12 hours or more. I possibly manage more servers than frogster at this point. However, I know that prior to a migration you do tests to make sure you can safely migrate the data prior to an actual move, but you do that while the system is down, not while it is running. The performance issues that have been popping up for the past week are tell-tale signs of them doing this data migration and testing while the servers are running (during PEAK hours no less) why else would every player on every server immediately get booted to login as soon as siege ended. 4 hours prior to the migration.
I have no issue with the 12+ hour migration, I fully understand that. What I want to know is who are the server administrators in charge of the migration and I truly hope you don't pay them that well.