Wow-Europe gets a 5-days credit for latency and hardware issues during August 31-September 12.  Blizzard President Mike Morhaime expressed his apologies and shared with the fans all the technical issues the Blizzard Europe team went through.  A good precedent, where fans are openly explained the problems that caused the lag spike and login issues.  Fans expressed they wish this type of communication more often:

On September 12th we detected a dramatic increase in temperature at different data centers. We then brought down the servers to avoid any damage to the hardware. Our ISP quickly identified and rectified a failure in the air-conditioning system; however, before re-opening the servers, we brought our hardware manufacturer on-site to check for any damage.