WWE's website posted a headline last night that says, "Shaq will not compete at WrestleMania." The article is accompanied by a photo of Shaquille O'Neal and Big Show going at it in the ring back in 2009.
HollywoodLife.com posted an article last week with the title, "Shaquille O'Neal: I Will Wrestle At WrestleMania 28." The HollywoodLife article noted that Shaq was asked if he would be wrestling at the event, to which he replied, "Yes, I'll be there!" WWE mentioned Shaq's HollywoodLife.com piece, but Shaq technically never said that he would be competing.
WWE wrote the following: "Despite Shaquille O'Neal's claim that he will compete at WrestleMania XXVIII in Miami, WWE officials have informed WWE.com that the 15-time NBA All-Star is not scheduled to appear on the card."