These “Deconstructing Buddhism” talks by Batchelor at the Insight Meditation Center are pretty good. Even if you don’t agree with what he is saying, at least he presents his case clearly.
In dismissing the ideas of karma and rebirth as features of ancient Indian civilization not intrinsic to what the Buddha taught, Batchelor points out that Buddhism has reinvented itself everywhere that it’s gone (from Japan to the Himalayas) to suit the needs of the new host culture. Buddhism is not a fixed, static thing, Batchelor argues—it’s more like a living organism. The question now is, what shape will Buddhist teachings take in the West?