Films - meh
I thought the Dune film was OK when I saw it, given what it had to squeeze into a small amount of time (though I had the advantage of having previously read the books)
As a fair chunk of SF audiences mainly seem to like "space opera" type of films (hence the success of Star Wars, which (IMHO) is the film equivalent of pulp SF) then I hold out little hope of a SF film being made that allows for the philosophical questions found in the best SF literature. (Though plenty of scope for mass audience appeal films of lightweight "fun" SF such as stainless steel rat etc)
There is far more scope for someone risking a series based on decent SF, as the best works typically need plenty off time to tell the story well
.. happily plenty of decent written SF out there to keep me interested so I'm not bothered how bad Hollywood SF "visions" are.