I think it is a little different when Kid is invited and then dis-invited.
If Kid had never been invited I would have just thought "Duff and Jo Jo, how lame".
I'm not sure it was confirmed...But then again, it IS the prerogative of the White House to reassess the "entertainment" arrangements, isn't it?
If the Bush twins want Kid Rock to perform for them, why can't arrangements be made for their own private party?
Then Rock can rap about "keeping it real," rather than diluting his "message."