Taylor Swift, Aerosmith, Rihanna, Usher, Bon Jovi, Lil Wayne, Green Day, Miranda Lambert, Mary J. Blige, Shakira, Pink, Psy and many others are set to take the stage at the iHeartRadio Music Festival 2012 in Las Vegas. The stellar lineup suggests the two-day marketing blitz to promote Clear Channel’s iHeartRadio digital music service is on its way to repeating the success of last year’s debut concert.