London's Daily Mail reports that Karimloo and Boggess will star in both the London and Broadway productions of Love Never Dies.
Lloyd Webber told the London paper, "I personally feel that what will now happen is that Sierra and Ramin will open in London early next year and then go to New York in the autumn of 2010. I think once the album comes out, hopefully before Christmas, a lot of singers will come out of the woodwork and we'll find new Christines and Phantoms for the other productions."
A recent casting notice offered this brief description of Love Never Dies: "In 1907 New York, the mysterious 'Maestro' who runs the theatre at Coney Island announces a one-off concert by legendary Parisian soprano Christine Daaé. Her arrival in New York with husband Raoul, Victome de Chagny and son Gustave, and their subsequent meeting with the 'Maestro,' bring the cataclysmic events of 10 years earlier at the Paris Opera crashing back into all their lives."
Sierra Boggess made her Broadway debut as Ariel in The Little Mermaid, which currently plays the Lunt-Funtanne Theatre. Her stage credits also include Christine in Phantom Las Vegas, Les Misérables, West Side Story and the world premiere of Princesses.