2010 is the last year for IPv4 and this has been foreseen as early as March 2010. However, the transition from IPv4 to IPv6 is a huge concern for the Internet at large because IPv6 has a different packet format and is not interoperable with IPv4. However, IPv6 makes use of routers more efficiently as compared to IPv4 and this will reduce the computational load from routers.
IPv6 will provide an intelligent mechanism for calculating the minimum size of data that can be transmitted between two end-points (read PMTUD). In short, the routers will speed up but the network cables will slow down.
The result of this transition is unknown though in theory, it should make effective use of the hardware. We will know soon when Akamai, Facebook, Google and Yahoo will participate in the first global trial of IPv6 on June 8. With their distributed servers spread all over the world, these companies will form the ideal testing ground and will churn up some useful real-time data.
IPv4 has been in use for three decades now and the test on 8th June will be a Game-Changing event.