I mean, you could do that. Somebody ends up in a place where David was and that serves as a Prequel to Aliens without having to go right into the Derelict again. Sure I could see that. Maybe not with Ripley but just because she's in it doesn't mean she'd do much.
If Cameron is attached, couldn't it mean he's only a producer? If he's going to be busy with Avatar (and yeah, didn't that die 10 years ago?) then he might just be a producer on it similarly to the current Terminator.