I just hope that although Ridley may not be interested in the xenomorph and Giger-like landscapes, practically all of the rest of the world is - and I hope he gets that this time round. Despite the first film's multiple flaws, the biggest one of all was that people wanted an Alien Prequel, and they got one, just without the Alien in it. That was why people were disappointed.
*And as for multiple Davids, I'd buy that notion simply because Fassbender is too big a box office draw to simply have round as a decapitated head for the duration of the movie.