The 200 member choir that served as the ensemble is comprised completely of alumni of the show.
Frances Ruffelle was originally offered the chance to reprise the role of Eponine, but she was pregnant at the time and couldn't attend.
Anthony Warlow was originally scheduled to reprise the role of Enjolras. However, both he and Philip Quast were starring in The Secret Garden in Australia at the time. At the last minute, the producers of TSG decided that only one of them would be allowed to miss performances to participate in the concert. Warlow had the bigger role in The Secret Garden, therefore, he had to stay. Because of this, Michael Maguire had less than one day of rehearsal time.
At the end of the concert, there was a reprise of 'Do You Hear the People Sing?' featuring 17 Valjeans from around the world. Each Valjean sang a few bars of the song in their native language.