THERE WAS AN update on the state of IPv6 at Defcon today, not really picking it apart, more where things are at. There is good and bad, but as always, much of it depends on the users and their motives. Lets start out with the good, IPv6 ends the whole idea that IP addresses are a scarce commodity once and for all. IPv4 has 32 bit addresses, v6 has 128, or 2^96 addresses for each v4 address, that is well more than enough. Better yet, Vista Beta 2 supports it natively, none of the mucking around that you needed to do with XP to get it running. Yay progress.
On the bad side, the plethora of addresses removes the need for NAT, or at least that is the prevailing theory. This is fine if you are using NAT for more IPs, but if you are using it for light duty security or anonymity, that is more problematic. Privacy has a good chance of going bye-bye with v6, but again, there are mechanisms to pseudo-randomize that info for a little safety.