To begin with, Stephen at Singpolyma has been doing some great work with both ends of the comment. First, Commentosphere continues to develop, and offer a way for us to bookmark comments that we write on other people's blogs into a central location. The latest inroads there, aside from a possible name-change, involve the development of an interface that will import more data from the source comment and require less in the way of manual transfer. The more information that the service grabs, (and the less it "interrupts" the flow of reading, commenting & posting) the more likely it is to be used, I think. The comprehensive import function will require blog owners to add a script to their sites, enabling the cross-posting of all comments to commentosphere. In a sense, then, this becomes a re-sorter / indexer of available comments, & instead of presenting them chronologically by post as on the source blog, Commentosphere would file them by author, or tag, or whatever.
In addition to enabling the manipulation of the comments that you leave on other blogs, Stephen has also developed a Blogger Comment Syndication Service to allow the output of a comprehensive comment feed from a blogger blog. See the Singpolyma Tech Blog:
For blogs that are set up per the instructions, comments are archived by the service as they come in, the service being notified of new comments via email, thus enabling the service to include new comments to old posts in the feed (unlike the Farrago Recent Comments Hack, which only shows new comments to posts on the main page).
These tools will integrate a user's comments into the stream of their activity in the blogosphere. The next level of tools being developed for blogs seem to be designed to bind sites together more tightly, and to draw information that is peripheral in terms of "virtual geography" into a more visible and accessible location. This is an interesting process, of which more in the coming weeks, I think... For my own ten cents... I wonder if we'll reach a point at which blogs no longer have sites, and authors simply publish feeds that are selectively grabbed & formatted to suit the reader. Then this will truly be a feedosphere....