Well that is weird, didn't stop working for me that I noticed but I think it may be finished now:

As a result of the FINAL FANTASY XIV All Worlds maintenance, the Lodestone maintenance which was scheduled to occur on May 25, 2011 from 2:00 to 2:30 (GMT) will now be conducted at the time below.

During this period, you will be unable to log into the FINAL FANTASY XIV Lodestone.

We apologise for any inconvenience this may cause and thank you for your understanding.

[Date & Time]
May 23, 2011 from 21:00 to 22:30 (GMT)
* The completion time may be subject to change.

(This is 22:00 to 23:30 GMT due to British Summer Time)

[Affected Service]
The FINAL FANTASY XIV Lodestone