Like I've been hinting I don't really know all the ways that it works, mostly just the names and modus operandis that are used if characters are selected.. Going back to the stuff about the Other, I totally believe the Other is working with Thanos until the very end and he does a lot of dirty work for Thanos, but also has his own goals through the dark side of matter. when he needs to retrieve items from distant locations he can travel through blackholes and anti-matter. I think the Other can enter Asgard now through the Tesseract or the Darkhold, but Thanos can't. Some of the negative energy within the tesseract comes from within reality, within the hypercube. And selvig talking about anti-protons in Avengers reveals its link to certain entities that dwell in the dark, inner and lower parts of the world tree connected to the dark world above and certain forms of magic that leave Malekith with a representation of the hidden negative, dark matter/anti-matter side of existence and black magic.. As the being from the dawn of time "The Other" has become the creator of black magic-- which will bring Strange into this in some way.
And we'll find out the Other is partially a demonic/magical being that Thanos utilizes for various purposes. But his own goals involve helping Malekith distract the Asgardians to retrieve a source of power from Asgard. In my theory we start to see how much of a threat the Other is before Thanos shows up personally in Avengers 2. The Other wouldn't be in GoTG but he would be in Thor 2. I know people really want to see Thanos have a major part in GoTG and Avengers 2. The thing about this Thanos is he even sometimes plays the hero representing his solo series from the comics. Thanos is sometimes an anti-villain and we may see this represented in GoTG. At one point a long time ago someone brought up a Thanos solo movie--but the basic idea has been folded into GoTG. In GoTG he's not really the main villain. I think part of Feige saying they may take their time relates to a lot of twists and turns with Thanos. Because initially he has control of a vast section of the Galaxy being challenged by the Church, and starts out as a Titan who some of the other galactic powers sided with over the Universal Church who was imprisoning many people. So in GoTG it's almost like the church seems worse than Thanos at first, and the intergalactic excons are on the run from other powers of the Galaxy when they first meet Thanos.
Now this means it's even likelier that he will be a main villain in Avengers 2. But I don't think he's the only villain.
I just think Thanos is the biggest piece of the puzzle and will have about as many starring appearances as Loki and Ultron by the end. If thanos stays alive in Avengers 2 we may actually see the gauntlet in phase 3... By far the main villains of the series would be these three who are planned to appear in multiple movies.
I think right now the Other is coming for Loki and was exaggerating a little. Thanos does know where he is, although I think Thanos can't enter Asgard. He can hide from Thanos in Asgard, however the Other can enter anywhere from the dark matter side of reality. So Thanos does make good on his promise but has to send his minion. He can still track down loki anywhere via this being who created black magic/dark energy in the ancient past. Scattering the Darkhold and leaving pieces of it in different realms.
And has left part of the darkhold with Malakith so he can get to the dark world easily, through blackwholes and anti/dark matter-- demonic energies.
Either way Thanos would appear in Avengers 2, I'm not saying he won't or won't be important, although his significance in Avengers 2 can be increased or decreased depending on a few factors + whoever else they use as lesser villains in that movie. The prob is the whole team can't take on Thanos one on one and some sort of other threat needs to appear to keep the less powerful Avengers busy. One more villain will seen taking Thanos's side but depending who that is Sterns, or Ultron-- it may change the ending for Thanos. In short I think they could even go half and half. Or Thanos would either return again after the second movie, or be stopped in the second movie and possibly never get the gauntlet in favor of a Masters of Evil avengers 3. Let's say they do drive Thanos back and Ultron is sort of covered instead for the first time as a main villain, while Thanos steps back into the background. Ultron would be covered and Thanos can be a returning/main threat for the entire series.
Certain things are there for much later. Thanos needs to be followed up on in some way in Avengers 2.
E.g. The Atlantis easter egg on the map in IM2 and Oracle being present at the Expo. There are plans for where this will lead, but the Atlantis references placed in IM2 may not be followed up on for a number of years, because they're significantly more throwaway than Thanos. There are definite plans for a Namor movie, but now it's far on the back burners.
Things like clues leading to Atlantis have been planted with no real plan in mind, while other things are a little less throwaway... However, there was a loose plan to work towards Namor at one point. They did want to use him, they just didn't know as much about how they want to use him as they do Thanos and characters they will need and don't want to skip like Strange and Black Panther, who take more priority now. Namor is extremely low priority in the grand scheme of things, however things are in place to pick up and expand on that map behind Fury in IM2, should they need a last minute direction for another phase 3 movie. it's like they allow for many things to change, while still following a general plan, to not force too much on individual directors...
These are things Shield does know about at this point, but the characters and audience don't. Like Atlantis.
In the trailer Mandarin seems to be calling out Shield. He mentions them by name.
He may know a lot about Shield and other things that are here mainly as hints of what's to come.
And now with the way things are planned we may not even have a chance to see much Namor unless he gets a solo movie after phase 3.
Certain characters like Black Panther and Strange will be included in this at all costs. Even miss marvel has a better chance at showing up in the movies now over Namor-- with the TV show and everything else in place any character could really show up. But Miss Marvel is higher on their list than Namor originally was because plans change, and sometimes they plan for things to change.
They dropped a lot of the loose plan for Namor because they're working towards something bigger than using Namor in a movie. As things changed and grew the plan for Namor to have his own movie has been pushed way back. Even the Inhumans might have to wait. .
This doesn't mean Atlantis was referenced for nothing, just that we might not even see it until the very end or even after phase 3.
Certain pieces are as interchangeable as the iron assemblers but will still fit the overall design. Certain things that are planned can be moved around or pushed further down the line, but with Thanos he has to be there in some capacity in Avengers 2...
"The evil Elder God known as Chthon
put into writing all his evil works and spells. It remained as the Darkhold after most of the Elder Gods were slain by the Demogorge
both managed to escape, but each were later banished to other dimensions.) [ Substitute Set with Surtur in some ways + parts of when Surtur was imprisoned within the earth...] Originally a collection of parchments, often refered to as the Cthon Scrolls, the pages were later bound together into a tome as "the Darkhold." Also called the Shiatra Book of the Damned
, or The Book of Sins
, the Darkhold has served as the source for other spellbooks, such as the Necronomicon
. The pages of the Darkhold are enchanted as to be indestructible, so that they may always serve as a conduit to the Earth-Realm for Cthon's influence and power.
Humans first found the Darkhold during the Pre-Cataclysmic Era , when the lands of Atlantis
were still above the waves."
So a lot of Thor would be about black magic and some of the rumors about Strange aren't entirely true, although there was a plan at one point. I honestly don't know if they're still following this but a lot of it would have to do with black magic. We'd be meant to think this is just Chthon for now and that the ancient/time elements & stone henge in Thor 2 don't have anything to do with time until a lot is revealed in subsequent films. This would mean Thor 2 would be exploring the dark magic connection and its connection to the dark elves, ancient earth looking warriors seen in battle in Thor 2 pics, the prime meridian, stone henge etc. Thanos doesn't know his minion is playing many of the villains and even met Surtur at the dawn of time. The Other may be much more dangerous than Thanos, and on equal footing with Surtur in intent/purpose (not powerwise). We'd slowly find out that his goal is the absolute destruction of all matter. He'll influence anyone he can and wants Thanos or Surtur to destroy the universe. his only purpose is to be able to talk to some of the major villains and possibly a backup plan for masters of evil to go forward should Thanos die in Avngers 2... He wants to destroy the universe by any means necessary and works from beyond material existence to return it to the state it was in before the dawn of time.