Maintenance likely. They couldn't have closed it for good because a few new items have been added to the web cash shop and web deposit is required to move those purchased items to your in game character.
As long as people are still purchasing from the cash shop the service will continue to be made available.
I wonder when its comes back since i gonna to be need for those speed pot and those other pots and item from the webdepot ... And i really need brown book ... Soon or later i gonna wast money on green book if the webdepot take longer then it did now ...
104