Life As We Know ItKatherine Heigl and Josh Duhamel, two of the most popular perennial romantic comedy leads, are joining forces in 'Life As We Know It,' due out Dec. 22, 2010.

Heigl and Duhamel play mismatched god parents to their friend's young child. After one date, they decide not to see each other, but when tragedy strikes the two must come together under one roof and raise the child.

Josh Lucas, Jean Smart and Christina Hendricks also star in this dramedy directed by Greg Berlanti.

Check out the trailer after the jump.