Whatever 'liberal' point this Archbishop thought he was making, it is fundamentally very very stupid to suggest that some people can break our laws because they have a different religion (if he didn't mean that, then what was he trying to say? Obviously as long as people do not break the law, then there is nothing to stop them abiding by their own 'religious laws'). His comments on Sharia law have made him pretty much a laughing stock, but I think it demonstrates where religion is going. It is clearly an attempt to form an alliance. The Anglican church is in severe decline, whereas Islam is growing in importance. Clearly Rowan sees it as crucial to join forces with all religions in his fight against reason.
*UPDATE* Here is an attempt at a defence for William's position.