"Given what we are seeing in the way of security issues on Vista I think it will be a while before anyone wants to trust their enterprise to IPv6."

Could you be specific? Because I think if you remove emotion from the equation Vista is fundamentally a much better OS.

But don't take my word for it...

Most resistance to Vista I see is cultural - it's "Different". Yes, there are a few technical issues - mainly software compatibility (which shouldn't be a surprise), but over all Vista is leaps and bounds a better operating system - especially for a corporate environment. The management tools built into Vista make XP almost a toy by comparison.

Oh yeah, Vista has a pretty decent IPV6 stack, and so does Mac OS X and Linux. The real issue is with the network equipment vendors (primarily Cisco). Until all pieces of a network are IPV6 compliant, it's pretty hard to make the switch. The analogy to Y2K is a good one - except with IPv6 there is no drop dead date - no zero hour to spur progress. I wouldn't be surprised if portions of the Internet never make the transition.