Nicki Minaj probably worded the following quote the way she did on purpose. Because she knows the reaction people have to the following word: movie! She has a movie! Let's read the news and play along with its version of Telephone: it's going to have, like, actors and distribution and marketing and everything! No. No, not necessarily. This is what Nicki Minaj said, as told to CBS. Essentially, she's defending the coherence and spectacle of her Grammy performance of "Roman Holiday":
"You know how people write plays and movies? That's what I did. I wrote that and I gave the world a tiny little preview of what was to come. And so I have to perform it on the set in which it would be in the movie, right?"
So in other words, Nicki Minaj wrote something, similar to how people write plays and music, and the Grammy bit was a "tiny little preview" of the full story. You know, the full story that got another tiny little preview with "Roman's Revenge," and that's been tinily previewed all throughout Nicki's career, from the uber-comprehensive Nicki Minaj Wiki to the easily findable articles from years ago to Pink Friday itself. Of course Nicki Minaj wrote a Roman Zolanski story, whether on paper or in her imagination. She's probably had it "written" for years; the only difference is now she's got the clout to hire Laurieann Gibson to execute this quote: "Nicki just truly wanted Roman to be exorcised, and I just went to work." (Read the rest of the article at that link; it's great.)
That's the story part. About the "movie," the most likely result--and this would actually be pretty awesome--is a super-extended music video along the lines of Kanye West's "Runaway." It could happen--"Runaway" director Hype Williams has worked with Nicki before, including that Grammy cutscene. You would watch all 34 minutes of a hypothetical extended "Holiday," right? Bound to be more interesting than "Starships."