I saw Slash's band there several years ago and was really disappointed. They played far too many GNR songs and it was just like seeing a covers band play the pyramid stage.
If I was there this year I'd be seeing Skindred, The Damned, Viagra Boys and QOTSA and just spend the rest of the weekend wandering around just watching random stuff, drinking poor quality, warm beer, sampling different food and confusing people who have had too many psychedelic drugs.