There does remain some hope for The Journal's future, however. If they can find a new server host, it's possible that a revamped Undermine Journal will make an appearance in time for Warlords of Draenor. However, in their news announcement, they caution that if the expansion's launch comes and goes without The Undermine Journal's reappearance, it will likely be gone for good. They will do their best to keep a webpage in place in order to deliver updates on the situation.
From those of us at WoW Insider, we'd like to thank Erorus, the creator behind The Undermine Journal, for all his hard work and dedication to maintaining such a wonderful resource. We hope The Undermine Journal's absence is just a hiatus, but either way, we'll see you at Realm Pop.