I wonder how much will be broken... will we get any stats on this?
World IPv6 Day
World IPv6 Day is an event sponsored and organized by the Internet Society and several large content providers to test public IPv6 deployment. It will start at 00:00 UTC on June 8, 2011 and end 23:59 the same day. The main motivation for the event is to evaluate the real world effects of the IPv6 brokenness seen by various synthetic tests. On World IPv6 Day, major web companies and other industry players will come together to enable IPv6 on their main websites for 24 hours.The goal is to motivate organizations across the industry – Internet service providers, hardware makers, operating system vendors and web companies – to prepare their services for IPv6 to ensure a successful transition as IPv4 address space runs out.
The test will primarily consist of websites publishing AAAA records, allowing IPv6 capable hosts to connect using IPv6. Although Internet service providers (ISP) are encouraged to participate, they are not expected to deploy anything on that day, just increase their readiness to handle support issues.