According to WWE sources, Chris Jericho will NOT be at Wrestlemania.
Don't count on Chris Jericho being one of the hundreds of cameos on Wrestlemania this year. Jericho was offered a cameo on the show ala Stone Cold Steve Austin, but turned down the opportunity to appear on the big PPV.
Inside sources in WWE say Jericho was not a priority, but on the "hundreds" list, and didn't want to be lumped in with all the rest.