The Cosmic Cube
In a bonus scene that runs after Thor's ending credits, Dr. Selvig meets up with Nick Fury in a S.H.I.E.L.D. installation. They'd like him to take a look at something they've found. Fury opens a metal suitcase to reveal a cube, about the size of a human fist, glowing with some kind of cosmic energy.
Ladies and gentlemen, The Cosmic Cube.
"The Cube" (it's assumed the movies will use the less silly-sounding "Tesseract") is the Marvel Universe Excalibur/Holy Grail/Aladdin's Lamp all-powerful macguffin, a "containment device" (series of devices, technically) of alien origin that houses massive levels of cosmic energy and gives anyone who can "control" it the power to reshape matter and reality itself at will. So it's a Magic Rock that grants wishes, basically. Its origins are convoluted in the extreme, but it ultimately ties back to the Skrulls, Marvel's perennial alien-invader heavies who have been heavily hinted at as prospective Avengers enemies.
Attempting to acquire/harness its power has been a driving goal for almost every sufficiently powerful supervillain in the Marvel canon at one time or another; particularly Johann Schmidt, AKA "The Red Skull," the antagonist of the upcoming "Captain America" movie, early publicity stills of which have indeed shown Skull actor Hugo Weaving holding up a cube-shaped prop. It also may be worth noting that in Iron Man 2, when Tony Stark is going through his father's declassified files, one of the items seen is a sketch of a hypercube.
I had a feeling this was coming, and the reveal still nearly knocked me out of my chair. Not only would I never have expected to see this particular item in an actual movie, its presence essentially busts the possibilities door wide open. "The Cube" is the ultimate "does whatever we say it does" handwave device in comic book lore, existing for the sole purpose of making whatever the writers want to happen happen "just because." Conceivably, it could serve that same function for getting Avengers scenarios moving with minimal setup: "Why are there dinosaurs in New York suddenly?" "Cosmic Cube!" "Where did that army of walking trees come from?" "Cosmic Cube!" "How are they on the moon, exactly?" "Cosmic Cube!" "Didn't that guy used to be played by a totally different actor?" "Cosmic Cube!"
The aforementioned Cube scene also drops another slightly-less-shocking point: Loki is still around, in some form (he seems to be either possessing or influencing Selvig). Interestingly, he seems to recognize the Cube.
Taken on its own, it makes a workable setup for future Thor sequels, though it does serve to remind fans that The Avengers of the comics originally assembled in the first place to fight Loki. Well, okay, actually they assembled because Marvel had pre-booked printing time and were coming in late so Stan Lee and Jack Kirby quickly thought up a team book using pre-existing characters in order to meet the deadline, but you get the idea.
Bob Chipman is a film critic and independent filmmaker. If you've heard of him before, you have officially been spending way too much time on the internet.