Not entirely true; there is a possibility for the non-Christian, by an "extraordinary" grace to be saved. I believe "Dominus Iesus," a document produced by the department formerly headed by the new pope, touches upon this, while still insisting that it is only Christ who saves.
I've always believed it in my heart. "No greater love..." Sorry if my generalization was flawed. I was just giving the impression I got from a quick google scan. Sorry if I didn't make that clear. FReegards....