Pretty much all of SOE will be down for around eight hours.

SOE will perform maintenance beginning at 12:01 AM on Thursday, July 26, 2012; this will impact the following services:

• Game Logins (across all SOE games) will be unavailable from 12:01 AM Pacific Thursday, July 26, 2012, to approximately 8:00 AM Pacific Thursday, July 26, 2012.
• Commerce transactions, including purchases on our websites and in-game marketplaces, will be unavailable from 12:01 AM Pacific to approximately 8:00 AM Pacific Thursday, July 26, 2012.
• Account management will be unavailable from 12:01 AM Pacific to approximately 8:00 AM Pacific Thursday, July 26, 2012.
• Forums will be unavailable from 12:01 AM Pacific to approximately 6:00 AM Pacific Thursday, July 26, 2012.
• Players who are already logged in will be logged out from the game.

Here's our Time Zone Conversion Tool to help you plan.

Source: Station.com forum announcement