Stowe Boyd at Corante with some thoughts about leveraging tags to create spaces for discussion, instead of simply link-lists:

Rather than create topical group blogs, people will simply coalesce around the same (or very similar) tags, which will define a topicspace, a tagspace. Today, we don't actually do much with those spaces: for example, all the posts tagged "PR" at Technorati don't amount to a real destination, like a group blog does, but is just a luanching pad for people to go elsewhere. However, if someone -- like Corante, perhaps -- were to aggregate the writings of people -- like the individual contributors to Many-2-Many, and let's say another leading 100 writers on things related to the human use of the Web -- tagspaces would emerge. "Web 2.0" would explode, for example. A company like Corante could direct some editorial digest on what the most interesting pieces are for any day, and that tagspace could become a real meeting point for people interested in the topic.

See LibraryClips for more thoughts on boosting the power, functions and use of tags:

Instead of pinging Technorati with a ThreadID system or a unique Tagback you could set up a “blog for threads” that you can ping, or why not just set up a service similar to Topic Exchange, but it would be Conversation Exchange.

You could have your own account space, like in del.icio.us, with an item list of all the conversations you have initiated, and also a list of conversations you have contributed in…maybe you could add tags to these linear conversations (or distributed gatherings) so you could organise, share and browse the portal by a conversation topic (a conversonomy even…he!..he!)

…this idea is simply leveraging on the Topic Exchange system by allowing a user space, and folksonomy features.

This is what will take tags & push them over the top. When they're statements of a stake in a community, rather than simple labels for search, then tags will be fulfilling a whole new function.