Don't ask how I got here, but I was looking at the revision history of a Wikipedia page and saw:
(cur | prev) 16:20, 18 December 2014 2607:f470:8:b044:3d66:5782:2dba:2c8b (talk) . . (9,582 bytes) (0) . . (→Dialethiesm may be a more accurate model of the physical world) (undo)
(cur | prev) 00:14, 30 November 2014 2601:e:8100:701:4124:33e5:9859:fc9d (talk) . . (9,582 bytes) (-19) . . (→Fixed ) (undo)
Yep, those are IPv6 addresses, doing minor edits on a Wikipedia page. Hell hath frozen over and the future is here.
This officially marks the first time I've seen IPv6 used for something other than testing IPv6 or demonstrating IPv6, or demonstrating that someone is an IETF wank.