I think it safe to say Fitz will return for season 6. He is still out there somewhere frozen aboard that ship taking the 'long way' to get to the future to meet up with the rest of the crew. As far as this season finale goes it was by far the best of the finales so far and one hell of an episode.

Could Coulson's deal with the Ghost Rider come into play in season 6? I really hope Coulson will be in those final episodes. It would not be the same without him in them.