The ability for people with certain domain knowledge or active interests to subscribe to tags, or customise their front page based on tags would be pretty nice.

The ability for people with certain domain knowledge or active interests to subscribe to tags, or customise their front page based on tags would be pretty nice. Example, I'm interested in travel related ideas/products, but I've really no great interest in much of the stuff on the front page at the moment. But if something travel related does hit the site I don't want to miss it. This might also allow for higher quality of comments, less eyeballs but more interested eyeballs so to speak.