Waypath chips in with some blogosphere innovation, a pre-alpha technology called Topic Streams. Looks like it's in the same vein as a lot of the Topic Tracking and Detection work, sponsored by DARPA, within the information retrieval community.
So innovation and build out in weblog related search seems to be picking up, but where's the new stuff on the authoring end?
A theory. For broad adoption, a weblog authoring innovation has to be browser based. Browser technology is really stuck.
There is one possibility though, some enterprising soul really pushes the integration of wiki writing with blog posting. When I say push, someone does the hard work of making this happen within a popular blogging tool like WordPress or MovableType, and polishes it so non-techies can deploy and use. Every blog post becomes its own wiki page, and a non-HTML syntax becomes used for authoring. This syntax then becomes extended with some features that people really get hopped up about.