Ideas for a sequel

Now that Prometheus has passed by, obviously as a setup for some bigger followings, what would be your favorite direction/plot for the sequel? It would be cool if they expand the theme into three seperate storylines, as follows: At the beginning we should see what did happen 2000 years ago on earth and on the moon, and then cut to Shaw in the spaceship with David. David somehow managed to repair himself and is almost fully functioning. These two leads on the trip should be the first of the three. Second, Weyland Corp. has picked up Shaws message and prepares another trip to the scene of crime, the moon. They somehow got the whole incident transfered to earth, now curious of the bio weapons and wanting to own them. The third is of course the Engineer world, also getting noticed what happend on the moon, and preparing an investigation. So if Ridley wants to pay the audience back, he better be more epic and, everyone knows how pissed he was not directing Aliens, so I believe he will deliver big time with double the budget and a PG-13.