Back in the day, there was a Norse God who went by the name of Thor. This Thor fellow was a mighty guy, in charge of thunder, and he wielded a magical war hammer that went by the name of Mjolnir. Thor travelled around in a cart that was drawn by a couple of magic goats that went by the names of Tanngrisnir (tooth-grinder) and Tanngnjóstr (tooth-gnasher). Thor spent much of his time hunting frost giants, going out smiting and generally adventuring.
On one particular adventure, Thor was caught up without food or lodging and made request of a a small family in a small home. The family--husband, wife and son--were incredibly hospitable in spite of not having the means to do so. In response to their hospitality, Thor decided to slaughter his goats and share the meat with the family. So there was a great feast but Thor told the family that there were absolutely not to break any of the goats' bones. The family's son was quite partial to marrow so he did not heed Thor's request and broke one of the leg bones to suck of the marrow. The next morning, Thor gathered the goat bones, placed them with the goat hides, waved his hammer and brought the goats back to life. One of the goats, as a result of the marrow suckling, had become lame. Thor, rather displeased, smote the son.
Now, for superheroes, the new lameness of the movie Superman Returns is equivalent to Thor's goat's lameness after the above recounted story. That is all.