So I updated to 0.3.18 and deleted peers.nxt the other day and since then I see neither localhost nor 127.0.0.1
Picking some of the peers' port 7874 I see my IP in their peers list, or better said in some lists I see it, in some I don't. In many it looks like my client would be dead, just 300-500 Bytes up/down, but then in one and another there was some activity associated and traffic ongoing now and then, so I assume it actually does something. Would be nice however if there was some indication on the own client's page as well.
And what's the difference between an orange "Address announced" bubble and a grey one? Most on those other hosts' peers lists were grey, including my own IP, my client's list only shows orange bubbles, and blue clouds of course.