SPrometheus made more than $400 million worldwide (although it underperformed stateside) — so a sequel seems like a safe bet. Except, according to one report, there's no forward movement on a sequel, because nobody can figure out what happens next after the first movie's somewhat baffling ending.
A report over at Bloody Disgusting claims that Prometheus could have been a standalone film that led directly into Ridley Scott's classic movie Alien. Instead, the studio pushed for a trilogy because they hoped it would make more money. And they hired former Lost showrunner Damon Lindelof to polish Jon Spaihts' script because they didn't trust the relatively untested screenwriter. (Bloody Disgusting claims Spaihts wrote the movie as a standalone, but Spaihts has claimed otherwise in past interviews.)
In any case, unnamed sources tell Bloody Disgusting that there's panic at Fox over how to continue the story of Dr. Elizabeth Shaw past the ending we saw in Prometheus:
Lindelof transformed Prometheus into a “trilogy”, thus stripping the first film’s conclusion of any meaning and setting Ridley and Fox up for disaster. This disaster was perpetuated when Lindelof announced he wouldn’t be penning the sequel. So, in short, the guy who convinced the filmmakers to make a trilogy, left them in the dust…
Sources close to the sequel have told Bloody Disgusting that the studio and [Ridley] Scott are literally “freaking out” over how to continue the story of Elizabeth Shaw (Noomi Rapace), and are taking pitches from basically anyone who can crack the story*. While a sequel is nearly inevitable, it definitely puts it in flux, and in a state of jeopardy.
The part about Lindelof turning Prometheus into a trilogy doesn't really ring true — and in any case, if the movie's ending doesn't lead to more stories that Ridley Scott wants to tell, the blame should rest squarely with Scott himself. He chose that ending, and it's not like anybody forced it on him. But it does seem quite plausible that nobody would have any good ideas about how to pick up the story where that film left off. [Bloody Disgusting]