Yeah, that does exactly none of the things I'm working on :). I'm not interested in replacing search, NerdQuery does an awesome job of that for me. I'm more interested in creating a content discovery tool that makes it easy for someone who hasn't followed me to discover things I'm doing based on interests they express, without having to know the exact keyword I picked for a tag. Lots of semantic analysis and relationship building involved… because I also don't want to have to think about it. Just write posts and let it do the rest.