All U.S. servers will come down at 7am PDT on Wednesday, July 18, 2012. The expected downtime is one hour. The EU servers will be coming down at 5am London Time on Thursday, July 19, 2012. The expected downtime is two hours. Here is the patch note:
Fixed a bug with Amygdalan Protectors in Dungeon Maker Dungeons.
SOE has also reported that some Dungeon Maker items were temporarily removed from the Marketplace, but will return after this patch.