Consistently across the Marvel version of Thor's various incarnations only the 'worthy' may lift Mjolnir, his enchanted hammer.
The inscription reads, "Whosoever holds this hammer, be he worthy, shall posses the power of Thor."
In the movie, of course, a large part of the story is centered upon Thor
In the comics and crossovers, many people have been able to wield Mjolnir, including Storm, Captain America, Beta-Ray Bill, Conan, a random paramedic (who hands it to an astonished Thor, laying on a stretcher), and Wonder Woman.
However, Superman wields it briefly in one crossover, but then can't lift it. Thor says Odin had briefly lifted the enchantment to allow Big Blue to use it.