Rucks himself, Logan Cunningham.
The lines were written by Supergiant's Greg Kasavin and recorded by Cunningham. According to Greschner, the surprise "floored" his bride as her wedding was narrated in real time with lines like "You ain't likely to find a nicer couple than Mr. and Mrs. Greschner." Of course, reading the lines is nothing compared to hearing them. Head over to Ars Technica for the full experience.