Apparently CPE means "customer premises equipment".
It's nice to learn that the real reason IPv6 isn't well deployed is that it doesn't work well enough to deploy. But if it doesn't work well enough, what is it that Cisco is selling? Is supporting it properly just too resource-intensive for a 200MHz MIPS with 4M RAM, so the specs need to provide a way to offload work to more-expensive routers upstream?
Heaven forfend that a router manufacturer might be obliged to ship with as much RAM as is found in any cereal-box-prize MP3 player.