User blog comment:DuelMaster93/Anime could return early 2014/@comment-108.16.14.40-20140120043523/@comment-7418318-20140120092158

We don't know. Mashima posted that he won't reveal where they'll pick up just yet.

With nothing officially told yet, we can only speculate. Many people hope they'll re-animate a few (or all) of the GMG episodes, then there's the chance for a re-cap episode and of course the question of whether they'll be adding Gildarts' "A Solitary Journey" story into the main series.

Or they might actually put some filler material in, like more details of F-Lucy's story (personally I think that won't happen right in 176, but only after F-Lucy revealed herself to the rescue team) or maybe some backstory about the Dragons (kinda like an extension of the Dragon Graveyard scene).