As seems to be the usual pattern, after the public test realms were brought online they were immediately slammed with traffic, bringing them offline again. As of writing this, the only test realm that seems to be up is the RP-PVP realm. The character transfer system suffered a similar fate, and was officially taken down
yesterday. There seems to be no news about when we can expect transfers or the test realms themselves to be back online, but as soon as I find out anything, I'll pass it on.