"features that I would like to find in a service: respectful of user rights, ad-free, built upon open source software, and with auditable results"
Well, well, well. For me there's only one single feature of a search engine that makes it a go or a no-go: have a damn good indexing engine that can provide relevant results in a timely manner. Everything else is just a load of crap that I will never care about. If I can't find what I'm looking for, that I couldn't care less how it protects your rights or whether it is open source or not. Oh yeah, about that auditability... forget that. I don't want to find what other people think I should find, I want to find the best match for my queries. That said, good look, develop away, maybe you'll indeed make a better indexer and ranker than Google's and we'll be all better off.