Comment 4 for bug 176125

RFC 3041 is not without controversy. For example, see "RFC 3041 Considered Harmful" (an Internet-Draft and thus work in progress; I could only find an expired copy, but haven't found a reason why the underlying issues should have expired):

  http://www.6net.org/publications/standards/draft-dupont-ipv6-rfc3041harmful-02.txt

http://www.ietf.org/mail-archive/web/ietf/current/msg25047.html also notes that there may be per-application problems with deploying RFC 3041 addresses. See also section 7.8 of http://www.6net.org/publications/deliverables/D2.5.2.pdf.

At this point I'm very reluctant to make this change for 8.04; given the relative rarity of IPv6 usage among Ubuntu users I think it is unlikely that we would hear about regressions in time to correct them. I think the best course of action for the time being is to document this in the release notes, and I've added it to my personal stash of items which I'll be documenting there.