Warner Chappell, the database of registered songs now lists new Madonna song Revolver. The songwriting credit is shared between six songwriters. Contrary to fan speculation, Madonna does get a writer credit, which means her version will not be identical to the leaked demo.

The writers are: Carlos Centel Battey, Steven Andre Battey, Dwayne Carter, Justin Scott Franks, Brandon Kitchen & Madonna. The song is produced by Madonna and Frank E and is featuring as a bonus track on the double disc version of Celebration.
We'd like to point out that Dwayne Carter is hip hop superstar Lil Wayne, which confirms his involvement in the track.

Sources: Warner Chapell, MadEyes, Madonna Fanzine
Graphic by Lukau13