I can't source this, so disbelieve it if you like, but Comcast and others are seriously looking at IPv6. The reason is basically that they know what a pain it

I can't source this, so disbelieve it if you like, but Comcast and others are seriously looking at IPv6. The reason is basically that they know what a pain it is going to be to switch. They want to get a head start, because they know that sometime they're going to ask for some new IPs, and actually be told "No." The trick is that v6 isn't useful unless both the clients, servers, and networks are doing it. Comcast and others will need to push on Level 3 and others. Fortunately, they're big enough that they can play the "I hope nobody else does this before you; we might need to buy transit from them" card.