If you mean bringing Gallifrey back, then I think it is a really exciting idea which will set the show in motion for the next 50 years. The show is all about change, which is what keeps it going, and Moffat well and truly understands that.
Well in a way I think he is helping the series because he looks like he's bringing back Gallifrey, and Matt, even though a dislike him, is quite a successful doctor. However in a way I think he is damaging the series as both Amy and Clara where effectively puzzles. Another reason I think he is damaging the series is his writing is a tiny bit sexist! Im not sure if this is a example or not but he made both Amy and Clara a puzzle while he made Rory the last centurion, which is not exactly a puzzle.