I like it. I'm curious how we'd tackle tag discoverability. If tags are suggested to new users, will they still be able to see the unfiltered stream?  If not, how do I find new tags?

Some ideas:
* "All" and "Subscribed" views. The "All" view lets users stumble upon tags that might interest them by seeing what's attached to stories
* A master tag list. This would likely require curation/organization
* Tags could be added/edited at any time. Refining tags on known posts could introduce them