Japanese newspaper Nikkei is reporting that Square Enix wants to support Dragon Quest X for the next ten years with downloadable content. Yes, ten years. The plan is to release new content for the game every ten weeks, with some of that content including story quests.
The newspaper report states that Square is looking to get "mid to long term earnings," and this is certainly the way to achieve that goal I suppose.
Dragon Quest X is doing a lot of things that's a first for the series, and a first for the Wii in general. It's an MMO, will have a subscription fee, and if Square Enix actually really supports it all the way through, could be the first console game to have the longest DLC schedule of all time.
Hard to see them achieving this goal, especially on the Wii or Wii U.