There will be some server downtime beginning early tomorrow morning for a game update (from EQLive):

All EverQuest Live Servers (except Al'Kabor) will be coming down on Wednesday, December 10, 2010 [sic] at 12:00 am US Pacific (US Pacifc-PST is -8 GMT: 1:00 am MST, 2:00 am CST, 3:00 am EST, 8:00 am GMT, 9:00 am CET) for a Game Update. The servers are estimated to be unavailable for 8 hours.

In addition to that, there will be downtime on Thursday for network maintenance (another note from EQLive):

All EverQuest Live Servers (except Al'Kabor) will be coming down on Thursday, December 9, 2010 at 1:00 am US Pacific (US Pacifc-PST is -8 GMT: 2:00 am MST, 3:00 am CST, 4:00 am EST, 9:00 am GMT, 10:00 am CET) for SOE Network Maintenance. The servers are estimated to be unavailable for 11 and ½ hours. This downtime is separate from the Game Update downtime on Wednesday, December 8th. We apologize for the inconvenience. Keep an eye on the EQ Players website and the forums for status updates and for news if additional downtime is needed.