…And what will she sing?  More below,

Adele will perform her Oscar-nominated song “Skyfall” at the Academy Awards. The tune, the theme from the James Bond film “Skyfall”, is up for Best Original Song against selections from Les Misérables, Ted, Life of Pi and Chasing Ice.
The Oscars ceremony on February 24th will mark the first time Adele has performed “Skyfall” live.