#1 - Feb. 9, 2010, 9:05 p.m.
When the realms are down for maintenance, the transfer services must go offline as well since they can not check the realms for your characters. Generally, once maintenance has completed on the realms and they are all back up, other services, like the Paid Character Transfer, start coming online a bit later. Maintenance is continuing at this point, but once it has completed you can begin checking the transfer site as it will be following behind it :)