A reader enlightens our ignorance of the hirsute hero:
Superman's already had several beards in the past. Here's a roundup, which sadly fails to mention my favorite Superbeard – Alex Ross' retired version of Supes in the graphic novel Kingdom Come.
Another offers more links:
Superman has been beardy in the comics and on TV. (Bonus pic of Conan O'Brien and Jarvis Cocker admiring each other's beards here.)
The Dish 