Thor is a superhero from another dimension called Asgard, which is a place where Norse mythology and future space technology combine. How does he travel from dimension to dimension? He crosses "the rainbow bridge," of course! It's a big bridge made out of a rainbow that stretches all throughout space! Oh, and the dimension we humans live in is called Midgard, in case I haven't lost you by now.
Powers: Thor is technically a god, I think. Or he's just from another dimension and therefore god-like to the rest of us. He speaks like he's improvising a Shakespearian play, all the time. He has beautiful golden hair. He also controls lightning using a hammer named Mjolnir. Nobody else can use its powers, not even lift it. Thor's just that special and strong. But he can't fly like most superheroes. Instead, he swings Mjolnir around until he's created enough momentum to fling it in the direction he wants to go and hold on tight! He can hurl himself pretty far, that way! He's also generally impressed by that human trait called "compassion," and it's the main reason he hangs around Midgard.
Back story: His father is Odin, ruler of Asgard. Sometimes Odin has to recharge his batteries and enter what's called "the Odinsleep." He sleeps for a very long time, so that's when the Frost Giants decide to attack! Could it be that they're led by Loki, Thor's evil and swarthy brother, a master of black magic? Worse yet, could it be that Loki has teamed up with The Enchantress, a sultry sorceress who likes to make people halucinate? And if she's involved, you can bet that The Executioner will be there! He's beefy and carries around a magical axe and loves to kill shit, and has a totally secret crush on the Enchantress.
Upcoming Film: Starring Chris Hemsworth, who played Kirk's dad who dies in the first ten minutes of Star Trek. Co-staring Anthony Hopkins as Odin and Natalie Portman as Jane Foster, a human lady EMT that shows lots of that human compassion thing that Thor digs.
The Big Question: How will director Kenneth Branagh give this extremely silly character a gritty/contemporary update? I have no idea, but dressing him up like a Vegas magician definitely doesn't help.