I can't see this film having anything to do with the Infinity Stones, as it needs to wrap up the Captain America trilogy and juggle various characters including the debuts of Black Panther and Spider-Man.
Although this film will be concentrating on Strange's origin and introducing the mystical and magical side of the MCU there's a chance we could see an Infinity Stone here. In the comics the Soul Stone has been a gateway to an idyllic pocket universe and Feige has talked about Strange exploring parallel worlds so maybe this is how the Soul Stone is introduced to the MCU?
-
Guardians of the Galaxy Vol 2
James Gunn keeps saying he wants to keep the Guardians separate from the main MCU storyline but I think this will be an important stepping stone towards Infinity War. With the GotG comics dealing with time travel this would be a great film in which to introduce the Time Stone.
Alternatively the Soul Stone has strong links with Adam Warlock in the comics and he has been hinted at already in GotG1. If either (or both?!) Stones turn up then presumably Thanos will be in possession of it by the end of the film. At the very least we should see Thanos retrieve the Power Stone from Xandar and/or the Reality Stone from the Collector.
I can't see any Infinity Stone involvement in the main film. However the post-credit scene could show what Thanos is up to between GotG2 and Thor3.
This has been stated by Feige as being the "game changer" of Phase 3 in the same way The Winter Soldier was for Phase 2. I would expect Thanos to take the Space Stone from Asguard at one point in this film and (if he hasn't already done so in Guardians of the Galaxy 2) take the Power Stone from Xandar and/or the Reality Stone from the Collector. Hopefully we will also get confirmation how/why two Gauntlets exist in the MCU.
Unlikely to have much Infinity Stone involvement unless Wakanda secretly houses one of the Stones as a power source etc. This film will bemore concerned with properly introducing Black Panther.However the post-credit scene will surely tease Infinity War Part 1.
I imagine by the end of this film Thanos will have his Gauntlet and all six Stones - however to get the Mind Stone he must surely kill the Vision. Also, it may be too much to give him all that power so soon, especially with two films inbetween Part 1 and Part 2.
It's a fairly safe assumption that this film will see a return to the Quantum Realm which for me would be a great place for the Soul Stone to be found - assuming all the Stones haven't already been revealed by the end of Infinity War Part 1. There's a chance this film will be taking place parallel to the events in Infinity War Part 1 which would increase the chance of the Soul Stone featuring.
An origin story but this is unlikely to be standalone since the character bridges the earth and cosmic strands of the MCU. We may have already met Captain Marvel in Infinity Part 1 and this will surely build up to Part 2 somehow.
The big showdown! All the Stones will be in play and presumably both Gauntlets... I'm thinking that the Time Stone could be used to undo some of the deaths caused by Thanos in Infinity War Part 1. We may also see an Avenger wearing an Infinity Gauntlet to fight Thanos.
Will the Stones be destroyed in the finale of Infinity War Part 2 or end up being given to different groups to look after? If they are given to different groups then the Inhumans would be prime candidates to look after one.