Before getting into the Clairvoyant's master plan, we must know who the Clairvoyant is. Like most people I'm banking on the Clairvoyant being Modok, or at least a version of Modok.
We now know that the Clairvoyant's identity will be reveal in Captain America the Winter Soldier, and as we all know Modok has an intense hatred for Cap, and has an extreme desire for world domination. We know the Clairvoyant has access to extremis, which further the theory of Modok being the Clairvoyant. We know S.H.I.E.L.D will be compromised, most likely by Hydra in Cap's sequel, possibly meaning Modok is now in control of A.I.M, Hydra, and S.H.I.E.L.D, giving him all the resources on Earth he could ever need to carry out his master plan. We know Modok has the twins imprisoned, and will most likely use them to carry out his plans, which could be the reason the Avengers won't get along with them at first. We know Cap will be made a fugitive in his sequel. We know Tony destroyed all of his armors, except his Igor armor, since his Igor armor was the only thing keeping himself and Pepper from being crushed to death. We know a Hulkbuster suit will be made in Avengers AOU, and it will do battle with the Hulk. We know there will be an army of robots, possibly an Ultron army in Avengers AOU.
Now for the Clairvoyant's master plan. First he wants to make the Avengers enemies of Earth. He's made Cap a fugitive in his sequel, most likely meaning he's done the same to Black Widow and Hawkeye. I believe A.I.M has gotten their hands on Tony's Igor armor and modifies it to make the Hulkbuster armor to force a battle between it and the Hulk, so that they will create so much needless destruction that they too will become enemies of earth. By doing this the Avengers will be forced underground, giving Modok the opportunity to create an Ultron army to help his super soldiers and the twins with his plan for world domination. The only problem is that Modok banks on being able to control the twins, but they end up joining the Avengers to help take out the Ultron army and Modok's super soldiers.
So what do you think? Is it a sound theory? Let me know below.