The following was just issued by WWE today on Facebook.
“Tickets for WWE WrestleMania XXVIII go on sale to the public this Saturday, but as a follower of our official WWE Facebook page, you can get your tickets to the biggest event of the year TOMORROW in a special online pre-sale, starting at 10 AM ET! Use the pre-sale code EPICNIGHT to get your seats, and we’ll see you in Miami April 1!”
Update (3:53 p.m. ET): A second code has also been released: SHOWCASE