Sorry, but under no circumstances should an ISP router auto route internal computers from the network. Thats just going to expose so many internal services, most consumers wouldn't even know they were running in the first place.

If we are to have a transition to IPv6, and I am very much in favour of this, then by all means make the addresses be globally routable, but force people to select the ports and addresses to be shared in their router. Otherwise we end up with another mess ala "open wifi".