Awesome idea. They made big puzzles out of this picture and gave it to their family members to open on Christmas morning. The most awesome birth announcement I've come across yet. I'm totally gonna do this!
*Love this shot, with the parents holding the chalkboard, and the kids just slightly out of focus; it would be even cuter if mom & dad were holding a picture frame, and if the kids were centered in the frame, but still incorporating the phrase.