IIRC correctly, Usenet did not have a machine readable syndication and aggregation format like RSS. That is the difference between the Usenet days and today I think!
RSS and tags are a winning combination for most things I believe!
there are some interesting discussions going on about tagging (keywords, folksonomies, etc) the net. A good starting point is with Scott rosenberg.
just to prove that history insists on repeating itself, 20 years ago, Brad Templeton suggested using keywords to classify USENET postings instead of newsgroups. I did some research on the idea that indicated to me that it wouldn't work (because people chose bad/stupid/inane/none keywords, and that you were better off auto-generating keywords than using user-created ones.
So of course, Brad and I fought about it. Knews never happened, and life moved on. And now, with blogs, it's back again.
for those curious about the past, and maybe able to learn from it and avoid remaking our mistakes: some useful links into google groups.