Well, Her Interactive posted about the game on their Facebook page. Let me quote the post verbatim:
Despite our best attempts to answer everyone's emails, posts, tweets, blog posts, etc. about Nancy Drew: Midnight in Salem...we admittedly do miss some. And hey, we’re only human, so sometimes we inadvertently miss responding to a post. Hence, we felt it would be appropriate to post the attached message. Our goal is to have a more substantial update for you very shortly. We appreciate your patience during this unprecedented shift at HeR Interactive. Please know that we are not ignoring you but we are a very lean team and simply can't respond to everything. We are doing the very best we can. Also, please know that just because we offer a new Nancy Drew puzzle or start a new Nancy Drew contest, that it has no impact on the development and progress of our next title. Our fans mean the world to us and we appreciate you sticking by us during this longer than usual wait time between titles. As always, we thank you for your support and stay sleuthy!
This came along with a picture which reads:
Please know we are still in the process of developing Nancy Drew: Midnight in Salem but do not have any additional news or a release date to announce at this time.
We apologize for this delay, as we are updating the game engine, UI, graphics and more to improve the overall quality of the games. We thank you for your patience.