Cordovan posted on the forums about some upcoming downtime:

The DDO Game Servers will be brought down on Monday, July 27th from 3:00 AM – 4:00 PM Eastern (-4 GMT) for data center maintenance and to launch Update 27: Trials of the Archons. Patch notes will be available during the downtime. Thanks for your patience, and we’ll see you back in the game soon!

Additionally, DDO.com will be unavailable between 3:00 AM – 12:00 PM Eastern (-4 GMT).

The first part of this work will migrate all of Turbine’s billing services to a new data center. After that work is completed, we will be updating the game to release Trials of the Archons. We will keep you updated on Monday.