As noted before, Mark Henry is going in for surgery today. While this isn't confirmed, word going around is that he's having surgery for the groin injury that he suffered a while back.
Henry said in the past that if he couldn't come back 100% from the injury, he would retire. There was talk before WrestleMania this year that Henry could be coming up on the end of his career.
Source: F4W
Damn that sucks.