According to Slashdot, engineer and author John Curran suggests that migration should happen in three stages. Between now and 2008 organisations should start to run IPv6 servers for non-production work.
Between 2009 and 2010, organisations would offer IPv6 for Internet-facing servers, which could be used as production servers by outside parties. By 2011, IPv6 must be in use by public-facing server and Ipv4 must be switched off.
Curran is only one bloke but he does cut a bit of ice in the North American Network Operators' Group (NANOG). Whether or not anyone will listen is another matter.
More here. ยต