If you play World of Warcraft on a regular basis we have good and bad news for you, the bad news is that some servers will soon be offline for 24 hours, the good news is that this is because Blizzard are preparing the servers for the Cataclysm expansion.
Blizzard are carrying out these preparations on a lot of servers this week, however other batches will soon follow, you can see a full list of the servers included in this initial group here.
The above mentioned servers will be going offline at 12.01 AM Pacific time this Tuesday (June 8th), Blizzard believe that the servers will be back online 24 hours later.
Currently a release date for the Cataclysm expansion is unknown, however now that the servers are finally being prepared I am sure it is not too far away. As we hear more regarding World of Warcraft: Cataclysm we will keep you posted, for more details regarding the server downtime check out the source link below.