Basically IPv6 is a protocol which gives us more freedom for innovation. It is inevitable; eventually we will have to get into IPv6. But we cannot overnight shift from IPv4 to IPv6. Both have to coexist. We cannot throw away our network devices and everything else. If there is a clear mandate on the IT manufacturers that all the devices being supplied today should be IPv6 compliant, and it is also driven by the end user, then this transition can be achieved swiftly. A similar thing is happening on the application side and the content side.
Security is another important reason to switch over to IPv6. It is something that is very important and because of IPv4 there are certain limitations to security.