Fedora because I used to participate into the project...

not really bookmarking as the author will put the tags but more of a way to retrieve/consume content by category.

I image it more like on twitter to start simple. In a second step having it as a collaborative mechanism.

Regarding the current volume, it seems already interesting to organize the post to be able to retrieve them later. For me, right now, SN is good for the immediate consumption but not easy to look for past posts. My 2 cts.

Missed the other post. If you could follow the RSS for a tag, it would help following specific subjects.