Re: Watch the massive wall of apathy and ignorance on IPv6 crumble gradually over the next few years.
"There was no reason for an operator to enable it before because there wasn't a phone they could supply without it being a support nightmare."
True up to a point, but I'd argue that in addition, enabling IPv6 as a mobile operator is a somewhat different challenge to enabling it as a regular service provider, and it's only in part an issue of whether or not a given set of handsets support it. For UMTS operators, for a long time the issues actually stemmed from the 3GPP standard in use that only supported a PDP context that was either IPv4 or IPv6. Supporting dual stack operation - which was considered very necessary, just as it is on desktop computers - thus required the creation of two PDP contexts. The increase in mobility and session management alone would have had a tremendous impact on available capacities in most operators' networks. Later versions began supporting multi-protocol PDP contexts, but it takes time to get this all in play.
Oh, and for networks with any kind of IMS services (for example), you have to handle devices with IPv6 talking to devices with IPv4, and so on.
Add on top of that the general lack of adoption for the protocol in networks as a whole (and thorough support from networking vendors) and you have a recipe for very slow adoption.