This code creates a new widget area which you can use to use to add a welcome message.
The code will work on any Genesis child theme and comes from the Ambiance Pro child theme by StudioPress.
You can grab the CSS to style your intro text widget the same as the themes demo from the child themes style.css file starting on line 1127.
This post answers this forum question:
I am trying to figure out how to create the intro text that is just above the main body of text in the post found in the Ambiance Pro