This is the first of two large version updates planned before the year's end.
From The Lodestone:
The previously delayed all Worlds maintenance / version update will take place at the following time. During this period, FINAL FANTASY XIV will be unavailable.
We apologize for any inconvenience this may cause.
[Date & Time]
Nov. 26, 2010 13:00 to 17:00 (PST)
* Maintenance completion time may be subject to change.
- FINAL FANTASY XIV
Check back for further updates, and discuss this now on the ZAM forums!