The Reality Stone (or Aether) is presumably still with the Collector after the Asgardians sent it to him at the end of Malekith’s failed assault in Thor: The Dark World. (Coincidentally leaked footage earlier this week had Thanos ambushing the Collector at his base for the Aether.)
Leaked footage?! I gotta find this. I already knew about the stone being with the Collector, but since it shows him only with two stones on Earth, I don't think he'll leave Earth to go get it until the end of the movie, after fighting everyone to snag the Soul Stone from Wakanda.
It'll prolly be a part 2 in Wakanda for the final stone. Bets on whose gonna die?
Fa sho Cap and Tony. Maybe Vision.
Yeah, I can definitely see some folks dying, and then Wanda reviving them with her hax powers (or Strange negotiating with Death, idk). If I had to pick some casualties, gonna guess maybe some of the easy pickings (Romanoff, Cap, Winter Soldier, Hawkeye) and maybe even Hulk. I don't think Iron Man, Spidey, Thor or any of the Guardians will die (maybe Star Lord/Drax).
Any chance Ultron shows up?
Maybe, they made him one half of the big bad in MvCI so I wouldn't be surprised if he makes some sort of cameo, but I don't think he'll do anything significant, nor do I want him to... these movies should be Thanos' party and his party alone.