The second single from Britney Spears' upcoming album "Femme Fatale" was posted on the internet on Thursday,  prompting Britney's record label to rush release the song today, several days earlier than planned.

"Till the World Ends", written by fellow popstar Ke$ha and produced by Dr. Luke and Max Martin, has critics suggesting that the 29-year-old's rollercoaster career is on the up again.

Check it out here, and decide for yourself: