Tagging of articles and comments has been suggested many time on HN over the years. Somehow, it never caught on. The powers that be on HN don't seem to want it.
It would be great it tagging was implemented anyway, by a third party if need be. I'd be all over that, and would have no reason to return to a non-tagged HN.
I think tagging/subdivision is a bad idea for HN. I believe subdivision is part of what makes the Reddit unappealing. There's a really good quote in The Diamond Age:
“One of the insights of the Victorian Revival was that it was not necessarily a good thing for everyone to read a completely different newspaper in the morning; so the higher one rose in the society, the more similar one's Times became to one's peers'.”
HN is valuable and interesting because of the diverse, eclectic, and elite crowd that reads the frontpage every day. Dividing it beyond basic "semantic" categorization (Ask, Show, Jobs, etc) would destroy that value.
I don't know. The problem as I see it is that there are disparate crowds of elitists all expecting HN to cater to their needs, and the first page (which is what most people probably only bother to check)only has so much space. Some people want to see startup news. Some people like politics. Some people consider any story not obviously related to programming or not obviously new to be a clear sign that the Visigoths of Reddit have broken through the gates and trampled down the garden.
I think it might be possible to add some more fine-grained discovery to the site without compromising its simplicty, perhaps, by putting it into user accounts. Something as simple as being able to store filters in a text field and being able to call them whenever. Bear in mind, that 'show' hadn't been up for six hours before people were complaining that it was destroying HN. If Facebook and Google (and Livejournal) have taught anyone anything, is that if you shove UI changes at people hard enough, eventually they'll tolerate them. They'll complain, but they won't leave.
Keep the front page as it is, if you like. Tagging would not prevent anyone from viewing an unfiltered version of HN. You could look at the "all" tag, or the default view could be untagged unless you wanted to search/filter by tags. Absolutely nothing need be lost.
Searchable metadata, however, is very valuable for those of us who are interested in particular subjects. For example, I'd like a way to filter out every iPhone, Android, Apple, Google, Facebook, startup, and marketing article that comes through HN without having to manually scan through each article.
True, I could do keyword searches through the title and body of each article, but tagging would make such filtering much more reliable.
Why would you want to get this in an email? I try to keep my incoming email to personal communication, and push any content consumption into RSS. Emails are for urgent stuff, and consuming this sort of content is anything but urgent.
I can give you an Inbox invite if you're curious about what the gmail team thinks the future of email looks like. It is a platform built around various functional groups that email is used for, which may or may not be urgent.
One nice thing is that this appears to be unpolluted by the larger affects of flag abuse and give what the user base at large thinks is interesting enough unfiltered.
Completely accidental, but yes: Because Hacker News Daily looks only at the number of points, it ignores the other signals which HN uses like flagging and "low-content" domains.
Ask Hacker News Weekly: http://www.daemonology.net/hn-weekly-ask/
Show Hacker News Weekly: http://www.daemonology.net/hn-weekly-show/
(The reason these are weekly rather than daily is volume: A daily top-10 for /ask or /show would include almost everything.)