Hmm, or you outsource the trust problem to your users. Let them select which domains to trust or who to trust to weight trustworthiness of domains for you.

Imagine that user A can create a list of domains with trustworthiness score. User B can then use that list by going to user-a-awesome-curation.koogle.com?q=nice+shoes

It might create filter bubbles but it would be transparent filter bubbles. You could even wikify/open source the curation.