Below is a listing of my posts on films that, at least at the time, seemed unlikely ever to get made. This includes both those films in "development hell" (announced projects which seem to have been serious initiatives at least at some point), and ideas for other movies which did not get even that far, but the possibility of which raised enough discussion that I decided to get in my two cents on the subject.
On Top Gun 2
Why the Wonder Woman Movie Hasn't Happened
Neuromancer, Coming to a Theater Near You? Looks Like It
The Return of Xander Cage?
The Matarese Circle – Coming to a Theater Near You?
A New Dirk Pitt Movie
Planning a New Dirk Pitt Movie
Dirk Pitt Returns?
Returning to Sahara: The Dirk Pitt Novels On Screen
That Jinx Johnson Movie . . .
Filming John le Carré's The Honourable Schoolboy
Robert Heinlein's Friday - Probably Not Coming to a Theater Near You
New and Noteworthy (Unfilmable SF Movies, Spy Movies, Futurism)