The following is an eXclusive Report that was not officially confirmed!

It took some convincing and a lot of great PR from Simon Cowell himself, but as of now Madonna gave her "OK" to perform on the X Factor this November, we have learned from a person close to Simon Cowell who asked not to be identified as negotiations were not made public.
ITV is planing a massive Madonna night, and changed the location of the show's live finals to a large enough venue for the queen of pop.
Madonna is actually showing some interest in meeting the finalists as well, after she, reportedly "fell in love" with last year's runners up JLS from videos sent to her by Cowell.
This year the live shows will air on Saturdays, but the result shows however moved to Sundays, Madonna is set to take the stage on November 1st, though that date is tentative and might very well change.
A final agreement is about to be signed in the coming days, if everything goes as planned, and an official announcement will follow.
We should note that The X Factor was the most watched show in the UK last year, and it has a big influence on charts worldwide.