The manga is still being printed, so the story should continue. From what I understand, the artist who made D. Gray Man broke their wrist a while back, or something like that, so the manga couldn't be made very quickly. As for the anime, there doesn't seem to be anyone saying it will or will not be continued. In theory, they'll probably start the anime production up again later on, when the manga gets a substantial distance ahead of where the anime is presently, like Naruto or Bleach is. We can only hope the anime'll start up again soon, huh?