IP addresses are running out! While I’m not about to start crying that the sky is falling, the article linked mentions that we will be out of IPv4 addresses in 2012 or 2013.
Considering most shops spec their network gear lifecycle to 4 or more years, now is the time to start paying attention to the needs on the infrastructure. We can all do out part today to ease the pains of this changeover. Any gear you buy today on your network, particularly the critical and perimeter infrastructure should either have IPv6 support today or have an aggressive roadmap to get there soon.
Also, for those budding (or bored!) security persons (again!), study up on IPv6 now. Learn how it works and how to implement and troubleshoot it.