Here is my idea
I had watched AVP-R with the commentary and heard that they tried to get I am assuming Adam Baldwin to reprise his role of Garber. Not sure why he wouldn't do it, maybe it wasn't a big enough part for him. It would be great to get him back to reprise his role from Predator 2 and play Garber, he could be the husband of Ms. Yutani. Also keep Robert Joy as Col. Stevens from AVP-R. Have someone play the role of Charles Bishop Weyland's son, Robert Patrick maybe, so they can show them working together as a joint company.
It should start about a six months to a year after AVP-R, but it will have the company of now Weyland-Yutani Corp. back in Gunnison, Colorado examining the landing pod in the lake that the predator used in AVP-R then transporting it back to a research facility. Then you can show another team in Antarctica getting the frozen Alien Queen out of the water (She was still alive when she was sinking). Once they get her out, they transport her to the same Weyland-Yutani military research facility complete with military personnel, where they took the landing pod, on a remote tropical island somewhere. They thaw her out and chain her up, in order to produce more eggs. They then maybe have military prisoners and use them as hosts for the aliens. Have to have someone comment on the notes made by Lex(AVP) that the aliens appeared in about 10 minutes, now they are taking hrs (in alien it must of been maybe 2 or 3 hours?)and the other creatures (predators) must of been giving the queen some sort of drug to accelerate the process.
There would have to be the inevitable disaster in order to get the Aliens to start running a muck. Then we see a ship that looks like the ship that was found in the first Alien movie and seen in the extended edition of Aliens, this ship is used by the Space Jockies (the big creature in the chair in Alien) and the Predators to transport Alien eggs to other hunting grounds. While they are passing by Earth they do a scan for the heat and conflict they crave, the monitors could show some battles in Iraq and Afghanistan and then they discover that the Aliens are running a muck on the tropical Island with the Weyland-Yutani installation.
So they cloak the ship and land at a remote spot on the island. All 3 Predators leave the ship and the lone Space Jockey is left behind. Some scientists and military personnel at the facility noticed the atmospheric disturbance from the ship and see it land and with the thermal suits (like Predator 2) they do a recon mission to the ship (do not go inside). They place a sophisticated homing device on the outside of the ship and return to the base. While this is going the remaining military personnel, scientists, Aliens and Predators are fighting it out on the island.
The Queen and a drone can end up escaping and on the way to the ship she lays her egg that will house a super face hugger with a Queen and drone embryo(as in alien 3). She then instructs the drone and face hugger that is out of the egg to head to the ship (just as she instructed the drones in Aliens to back away from Ripley). She then turns back to fight the remaining 2 predators.
The Drone and face hugger make it to the ship where they go to the observatory with the big telescope, where the drone knocks out the Space Jockey and then it is impregnated by the face hugger. All the Aliens are killed on the island and 1 Predator remains and after he kills the queen he boards the ship to leave. (There will be NO explosion to kill everything on the island) The predator takes off in the ship and once the ship is on course he then proceeds to the observatory room where he sees the space jockey against the wall passed out. He scans the jockey and sees the queen embryo gestating inside. The same face hugger tries to impregnate the Predator, but the he kills the face hugger. Then the drone emerges and a fight happens between him and the Predator. In the final blows of the fight, the Alien is thrown to the floor and he stabs the Predator through the neck with his tail and with his last breath the predator decapitates the alien and collapses on top of the acid bleeding drone. The acid melts a hole in the deck (Like the hole in Alien.) and the now melting predator falls down the hole with the drone.
You could then go back to the Weyland-Yutani scientist tracking the ship, and then go back to the Space Jockey ship a few hours later when the Space Jockey comes to. He then hops into the big telescope chair and then you can show the Space Jockey convulsing with the Queen trying to get out, he uses the telescope chair to locate a planet to land / crash on, he then resets the computer to land / crash on a planet LV-426(from Alien and Aliens) He then sets the computer to issue the warning signal, after that the Queen bursts out of his chest killing him. The ship crashes and the hull breach occurs and the atmosphere gets in and makes the space jockey look as if it has been fossilized, And then the Queen chestburster goes down the hole made by the drone.
Once the ship comes to a stop the last thing you see is the Queen going through the ship and then the camera pulls back and you see of all the eggs that Kane saw in the first Alien movie complete with the mist and the blue barrier. This is how Weyland-Yutani Corp. knows about the ship and Alien in the first Alien movie, because it has the homing device on it. Plus it has the warning from the space jockey that mother and Ripley deciphered in Alien.
I think this would be a good way to meld the story lines together.
Perhaps Shane Black, who has written a few action films and even starred in the first Predator movie could write and direct it to bring a familiar element into the mix.
