Someone previously posted a link that did not work for me and a few others. I emailed Publix directly and they emailed me the coupon in .pdf form. If you need the coupon or know someone who does, please PM me or leave your email address in this thread and I will forward it to you.
The coupon is $20 off a wedding cake order of $200 or more. Offer is good through April 30, 2010.
Hopefully this will help someone.