It's not just the concept or the stars. It's not an either/or situation anymore. For these prices, it has to be both. The concept helps, but it's the concept combined with actual stars in front or and/or behind the camera that differentiates John Carter from Avatar.
James Franco, the Energizer bunny of actors, plays Oscar Diggs, a small-time magician in a second-rate traveling circus first seen doing his show to a small crowd in the black-and-white Kansas of the early 20th Century.
From his Jean Valjean role in Les Miserables and his generous on-the-spot performances at various celebrations, including a lunch hosted by Ron Meyer, Hugh Jackman is truly a songman you want to have around.
What happens as the film goes on in is best left for viewing by Bourne aficionados. The script is thin, but the acting, cinematography and direction make up for this loss. This is worth seeing even by the naysayers.