Interesting question. I wonder if you could get into this list (without nefarious purpose) if you provided some major hosting service? Eg: I see k12-schools in the US are on that list, it would make sense to allow someone providing shared hosting to get on the list (to avoid users setting cross-domain cookies). Eg: appspot.com and blogspot.* is on the list[1].

More information:

  http://publicsuffix.org/submit/ (and the rest of the site, obviously)

[1] http://mxr.mozilla.org/mozilla-central/source/netwerk/dns/ef...