In a way, it exists: visit comp.misc where a small group of devoted usenet fans discuss HN-type things, and where a fair number of HN stories have been linked and discussed. Visit misc.news.internet.discuss for non-computer tech discussion (and some fluff), and visit sci.misc for science articles and discussion. Among those three newsgroups you have the sum total of HN and Slashdot, and a nice crowd of Usenetters.