Source: Cinemablend via Latino Review
According to their source, the actual big villain of the film will be Loki, Thor’s half-brother and nemesis who will also be the bad guy of this summer’s Thor, played by Tom Hiddleston. Latino Review says Hiddleston will be back to play the part, and in The Avengers he’s getting power from none other than the Cosmic Cube, that great force that’s at the center of the other big Marvel film coming this summer, Captain America. Loki gets his hands on the Cosmic Cube and uses it to summon- dum dum dum!- the Skurlls. Chaos ensues, Avengers assemble, etc. etc.
You know that plot seems very Loki-ish and is probably the only thing supporting that this rumor may have any truth to it. Loki’s character is known to be a trickster and a liar so somehow parlaying his way into possessing the cosmic cube that’s used in the Captain America movie sounds like a feasible way to marry the worlds together for a subliminal over-arching storyline that culminates in the Avengers movie. I like the idea, and think it would be a cool way to unite the heroes to lay the smacketh down on the Skrull empire.