The Undertaker's participation at WrestleMania XXIX seems to be up in the air.
This week's Wrestling Observer Newsletter notes that Taker is uncertain that he is physically ready to perform at this year's show.
The original plan was for CM Punk to be his opponent.
The article points out that he wants to go out there and put on a stellar performance like he has done at recent WrestleManias and feels that he is unable to at the moment.
He hasn't wrestled since last year's Mania, which sort of tells you how bad his condition must be.
With that said - I'll believe he isn't going to play a part in 2013 when the WrestleMania hype heats up once February's pay-per-view is over and he isn't a part of it.