Considering nearly 10 minutes of footage from Tarantino's latest opus recently screened in Cannes, a trailer, or possibly just a teaser trailer, playing in front of Scott's sorta-"Alien" prequel doesn't sound out of the question. And while studios generally like to promote their own, this sort of cross-promotion isn't out of the question. As you might recall, Warner Bros. placed their "The Dark Knight Rises" prologue in front of IMAX screenings of "Mission: Impossible -- Ghost Protocol" in December. So maybe Harvey Weinstein greased Tom Rothman's palms, who knows, but certainly the geek crowd is exactly who they want to get excited out of the gate.
Oh, and the other rumor going round is about those additional co-stars in "Django Unchained" that Harvey Weinstein said could still appear in the picture. Word has it one of them is Michel Fassbender who had a small role in Tarantino's "Inglourious Basterds" (and of course also co-stars in "Prometheus," how fitting). Sounds feasible, but as of right now, it's just an unconfirmed rumor. Though someone does claim to have seen Fassbender on set... "Django Unchained" is set to open on December 25th.