Not that she's been asked, or expressed interest, but OMG she should totally do it. She can sing the song she's famous for, I Dreamed A Dream That One Day We Will Have A Day Free Of Royal Wedding Headlines.
What bothers me is that Joan Rivers is going to be invited. She was at Prince Charles and Camilla's wedding and like 200 people were invited to that. WTF, British Monarchy? You can't find any other Americans to invite? How about Barack and Michelle Obama? They'd class up the place. Hell, even Joe Biden would probably bring along a decent gift. I would avoid Republicans, though. They're not big on anything being paid for by the state, so.