Blogging on the open web today still have a few shortcomings that some closed blogging communities have overcome: comments, and threads spawned from comment discussions are seldom threaded, and seldom leverage the exchange of ideas and developing topics at any depth; it's more of a hit-and-run business. You drop a few words, perhaps a link or two pointing to something you want to refer to, and then you essentially hang up.
If your comment ever gets any attention, it's most likely through some other channel -- mail, or a note in your own blog -- that does not end up visible to other visitors who got interested in your exchange, or at least not where they are likely to ever find it. This is of course not ideal. I'd like to change that. This probably takes some architectural thinking and innovation. And, if it is to change anything substantially, it must be really easy too for the end user. Easier than trackbacks. Of course it's a difficult problem, but it's one worth solving. Being Blogger might be one place to start; after all, that is one possible vector at solving part of the problem, between blogger members. It's always easier if you have some level of control of both ends that meet.
Another feature often found in more or less centrally organized web communities is the back tracking option of reading up on what someone has posted, in other threads, through a specialized comment search facility or a link from the user's profile. I often feel I would like the same thing on the chaotic web, too -- maybe as an opt-in system, where each commenting opportunity also offers you the choice of trackability or not; essentially whether your comment will end up on your "my comments on the rest of the world" roster.
I've started brewing ideas on how to implement the latter, again starting with Blogger (and perhaps HaloScan), with some client side support from a GreaseMonkey userscript you install (since I am no Blogger tech in a position to develop this on their comment form directly). When you visit a blogger comment form, it adds a check box "Add this comment to your comments list" that is checked by default, and stores a permalink to your comment on a central server when you post it.
Add some support on the central server to pull in all of your comments to some page of yours and format them however you want, for instance like the deli.cio.us JSON feeds, and we would be up and running. I will probably look in to making an application along these lines at the Ning playground (a free hosting place for developing social applications with some nifty supporting back-end architecture).
Might be a good idea to add some kind of tagging features to the concoction, too, so you can pull in your comments as RSS feeds by topic, as well, so tech commentary doesn't get mixed up with personal relations comments unless you really want them to.
Your own thoughts, dreams and wishes are of great interest, of course; I'm not likely to come up with even all of the obvious thoughts and ideas on my own. :-)