Blade Runner and Alien universes may be the same
An extra on the Prometheus Blu-ray indicates that Sir Peter Weyland once knew Dr. Eldon Tyrell.
First, some in-cannon background on both characters:
The Tyrell Corporation is responsible for the construction and deployment of "replicants" in Blade Runner, the film adaptation of Philip K. Dick’s novel Do Androids Dream of Electric Sheep? The Comapny is called the Rosen Corporation in the novel, and plays very little part in the story, but Tyrell plays a large part in the film, and even features its owner, Eldon Tyrell as a significant character.
Not much is revealed about the origins of the Tyrell Corporation, but it’s obvious that Tyrell himself was a genius engineer and programmer, and so likely had a hand in creating the first Tyrell products.
The company specialized in building "replicants." In the novel, they are simply called androids, but that implies that they are robotic, which is not true. Their composition is nearly indistinguishable from a human, and their parts are all biological.
The difference is only that they are manufactured, rather than born, and that they have been given a set life-span of four years, to ensure that they do not become to emotional or powerful.
By the time of the events of the film (2019), very few of the parts in the replicants are still mechanical (the eyes seem to be one example), instead relying on mostly genetic engineering to ‘grow’ the devices, making them visually and tactilely indistinguishable from human adults.
The newer replicants in the film are given histories in the form of fake memories. The love-interest in the film is a Nexus-7 prototype called Rachael, who has been loaded with the memories of Tyrell’s adult niece. The thought is that these memories give the replicant something to fall back on; something to cushion the weight of the massive intake of new experiences.
Weyland-Yutani is the ever-present "Company" the characters must oppose in the Alien franchise of films.
They play little direct role in the first film, other than to be a name on the characters uniforms, and a distant, mysterious employer, which the characters never refer to by name.
Actually the name on all the uniforms was "Weylan-Yutani"- which was simply intended to sound international, being the combination of a British and Japanese name; it was changed slightly for the second film, when the characters had to start dealing directly with the company, and even say the name a few times.
In the retro-canon of the story-world, Weyland-Yutani becomes an illuminati-level force, with its hands in almost every major technology and human event in the galaxy. It is revealed at various points that the company even owns the earth’s military force, the Colonial Marine Corps., considering them just another investment, a "military-branch" of their technology holdings.
In Prometheus, which takes place in the same universe as Alien - and is set in 2093, we get to see Sir Peter Weyland, founder and CEO of Weyland Corp, a sister company to the pre-Yutani Weyland Industries - the canon is a little fuzzy on how Weyland Corp and Peter are related to Weyland Industries and Charles Weyland, but it seems like all of it eventually becomes Weyland-Yutani.
Sir Weyland's greatest achievements and patents are in Robotics, and the pinnacle of his art is David, a highly advanced, learning android, very different from the replicants of Blade Runner. Weyland was just getting his robotic firm started during the time of the events of the Blade Runner film.
With that in mind, we find this paragraph in the 'personal logs' of Peter Weyland, contained as an extra on the Prometheus Blu-ray, as pointed out by an eagle-eyed Redditor:
"A Mentor and long-departed competitor once told me that it was time to put away childish things and abandon my "toys". He encouraged me to come work for him and together we would take over the world and become the new Gods. That's how he ran his corporation, like a God on top of a pyramid overlooking a city of angels. Of course, he chose to simply replicate the power of creation in an unoriginal way, by simply copying God. And look how that turned out for the poor bastard. Literally blew up in the old man's face. I always suggested he stick with simple robotics instead of those genetic abominations he enslaved and sold off-world, although his idea to implant them with false memories was, well... 'amusing,' is how I would put it politely."
It's pretty clear that this is intended to show a connection between the two characters, and thus insinuate that they share a story-universe. Of course, it doesn't make any sense with Philip K. Dick's original novel, and it's unlikely that filmmaker Ridley Scott ever intended for them to function together, but one wonders if this is the first glimpse of an attempt to combine the worlds, or just an amusing tid-bit thought up by one of the writers responsible for coming up with misc. extras.
Honestly, I hope that this is not canon, especially with a new Blade Runner film on the way. If we see Peter Weyland play a central role in the new film, that would be a shame; The Blade Runner franchise deserves to stand alone.
However, it might explain why Ridley hired a young man to play a very old man in Prometheus: if he was planning on using the actor again in another film, in which he would need to be much younger.
After how terrible Prometheus was, however, I have a feeling I'm just going to be ignoring the new Blade Runner film anyway, at least from a canon perspective.