I found a Register article on IPv6 Security that provided the link to an IPv6 talk at DEFCON 2010 - Who Cares About IPv6?. At first I thought the Register article was a little over the top but reading the calmer presentation explained the issues in a much calmer fashion. Yes, we'll be having many IPv6 growing pains. Yes, we have a lot to learn. And yes, it's going to be painful. Plain and simple, we don't know what we don't know. Both articles and the supplied links are useful so I recommend reading both.