All SOE game servers, including all TCG and MMO servers, will experience downtime tomorrow as they are taken offline for hardware maintenance.  This downtime is scheduled to start at 3am PDT and will last approximately 4 hours.

According to Jason "Pex" Ryan, this is to "Replace VTT modules (voltage regulators) on Core Koll switches 2, 3 and 4" in our network operations center".

See the official notice on the EQII forums and other SOE game forums.