I guess I'm exactly the audience for this, because I'm really happy to see old favorites like Supergrass and the Lightning Seeds (and even Busted and Bjorn Again were great fun the last times I saw them at IOW).
On the website, they go into more detail about the day splits:
Friday Main Stage
Sting, Faithless (closing), The Corrs, Amy MacDonald, Lottery Winners
Saturday Main Stage
Stereophonics, The Script, Paul Heaton featuring Rianne Downey, Busted, The Saw Doctors
Sunday Main Stage
Justin Timberlake, Jess Glynne, Texas, Olly Murs, Alison Moyet, Ella Eyre, Björn Again
Thursday Big Top
Example, The Pigeon Detectives, The Smyths
Friday Big Top
Clean Bandit, Dean Lewis, The Lathums, Crystal Tides
Saturday Big Top
Supergrass,
Sunday Big Top
James, Lightning Seeds