Do you have a link to a story -- except the RUMOR from WND -- that he was scheduled to appear?
From the NYT News Service:
The Bush twins, Jenna and Barbara, will be hosts of the youth concert, where the teenage singer JoJo will appear along with Kid Rock.
http://deseretnews.com/dn/view/0%2C1249%2C600102390%2C00.html
This whole thing could very well be a non-story. No one has said he was even invited in the first place, not even the WND. My guess is that they assumed he would be, because of his appearance at the convention party. As to what is appropriate at the Inauguration...it seems to me that this is the one day out of four years where the President gets to celebrate as he likes. It isn't for the WND or even us to tell him whom to invite. Personally, I think Kid Rock has no talent and his change to country western was trying to get an audience. But that's my opinion. I certainly won't tell any one who or what they should like or dislike; or whom to invite or not to invite to their celebration.