It was written in my local paper how Paul McCartney and Bono were clashing and that Paul wasn't going to do Live 8 unless he was opening and closing the show.
I also found this on u2log.com. I apologize if this was posted already.
Are you ready for U2’s hit and run performance at Live8 this Saturday? The band are kicking off the day at London’s Hyde Park, playing ‘St Pepper’s Lonely Hearts Club Band’ with Paul McCartney and then, according to a schedule sent out to affiliate broadcasters, a short set of three songs: ‘Vertigo’ en ‘Beautiful Day’ and ‘One’. After their Live8 performance they will jet it over to Vienna to continue their Vertigo Tour on the same day. It’s not as impressive as Phil Collins’ Concorde stunt 20 years ago, but a valiant effort nonetheless.