Ok guys this shouldn't take too long, its just an idea I've had after reading something online.
In the CBR Report of the set visit, they mention:
'Thor, vanquished to Earth on a journey of self-discovery where he encounters Natalie Portman's Jane Foster, his first contact with the modern human race.'
Is this just me reaching, or does the word 'modern' hint that Thor's been to Earth before? I may be reaching here, but maybe this is a hint that Thor's been to a slightly older Earth, perhaps in wartime? The time of a certain super soldier?
From there, I did a little more thinking. Just follow my train of thought on this, but Caps shield in comic mythos is made up of Adamantium or Vibranium, yeah?
Adamantium can't be used because sadly, Fox has the rights to X-Men.
Vibranium comes from Wakanda, so that means if the shield was made in WW2 then Black Panther must be old... but then if they intend to make a BP movie then that mean it'd have to be set in WW2 in order to follow MCU continuity.
BUT, and this is a damn big but if you dont like things changing between comics and movies, Thors hammer looks pretty metallic in the Poster/teaser. Now a few users have already spotted this, it may just be the effects or maybe they've changed the hammer to metal.
Why does this matter? My theory is this:
Odin and a younger Thor come to Earth in WW2, meets with Cap and as a gift from Asgard to Earth, give Howard Stark some of the metal. Howard then uses this to create Caps shield. The gift is as part of a peace deal between Asgard and the new SHIELD Organisation.
This then ties into the Thor scene where Coulson is interrogating Thor: SHIELD fears Asgard is breaking the peace agreement and steps in. By the end of the movie Thor and SHIELD are cool and thus agrees to help them amongst the threat Earth faces in The Avengers.
This also means that Thor couldn't damage Caps shield, giving greater strength as the leader of the team.
I know it's a bit of a stretch, but it is a possibility right? What do you think?