I dig this! Since you're full-text indexing blogs with an eye towards content discovery, can I tempt you towards building out a reverse link index function to enable me to browse by thread?

My use case: often times blogs will respond to other blogs, linking to the original post in the process. The nature of linking means it's very easy to follow threads backwards in time, but given the original post it's often hard to discover the responses and ongoing conversation to follow things downstream. I'd like that downstream browsing to be easier.

My hope would be that such a tool could unlock higher-quality discourse. As a reader, this would let me hijack my natural tendency to follow comment threads, and redirect that attention towards slower-paced, more nuanced, more focused writing.

Edit: hmmm... though looking further, maybe this goes against your MarketRank philosophy.