Perish the thought, but Hall and Oates supplied Jagger's band at Live Aid on the same site.
The Dylan/Wilco/Morning Jacket tour doesn't start until 6/26. So maybe Bob can join them for Brown Sugar (a nightly inclusion in Dylan's fall 2002 set lists).
Silvertide. Great small band from Philly that just reunited this year. They played one reunion show in March, and covered Sympathy For The Devil in the encore, talking about how the Stones always had that harder edge to the Beatles and the songs are meant to be played live, with passion, and to give any show that extra boost. They are huge fans, it would be a great push for them, and they'd do an excellent guest appearance.