If the Odin Force determines who is worthy to receive the power of Thor then Loki may have a thing or two to say about that

What makes a person worthy to wield the hammer of Thor? Screen cap
from the upcoming Avengers: Age of Ultron. The clip aired last night
during the Agents of S.H.I.E.L.D. scheduled broadcast. 

Last night, during Marvel's Agents of S.H.I.E.L.D.'s broadcast, they ran a cut scene from the upcoming Avengers movie, Age of Ultron. Gathered around the coffee table in Stark's tower were the Avengers, all taking turns at lifting Thor's hammer Mjolnir. The only one that even came close was Steven Rogers, a.k.a. Captain America. Thor's hammer budged, which made Thor just about spit his beer, but the scene resolved itself in that this is all that happened, leaving Thor self-assured that he alone remains the possessor of the "power of Thor."

But it does make me wonder what makes a person worthy to lift Mjolnir in the first place? Do you have to be a warrior? Do you have to be pure of heart? Do you have to be willing to kill? Do you have to be honorable? Do you have to be humble? Or is it all of the above? The comics have given us over a dozen characters through the years that share all or some of these traits (and yes, Captain America was one of them).

So here's what I think: the enchantment placed on Thor's hammer that reads: "Whosoever holds this hammer, be he worthy, shall posses the power of Thor" has to do with Odin's will (or perhaps his bias). And since Odin wields the "Odin Force," which is the most powerful magic in existence possessed by the king of all Asgard, I am drawing a strange but inevitable conclusion: if my theory is correct about the Odin Force being ultimately responsible for judging the wielder of the hammer "worthy" then at some point Thor's going to be in big trouble.

Thor without Mjolnir from a screen capture of the Avenger's Age of Ultron
trailer. Is Loki responsible because he now wields the Odin Force?

Recall please last year's movie Thor: The Dark World. At the end of The Dark World (weak spoiler warning but you've had a year) Loki deposes Odin to sit on the throne of Asgard. If Loki now wields the "Odin Force" then the magic that serves as the enchantment on Mjolnir will have to start reflecting upon the new ruler's biases. Loki has no honor, so it's quite possible that Mjolnir at some point will find its way into a villain's hands. I think we may have gotten a small hint of this in the Avenger's: Age of Ultron trailer with what looks like a very upset Thor turning his eyes to the heavens and screaming (and he doesn't appear to be holding Mjolnir at all). Now keep in mind that this is purely my speculation. But don't you think it would be interesting if Thor no longer being able to lift Mjolnir was the first clue that all is not right with the Asgardian throne?