I think SearchWiki solved a different problem. It was about, approximately, globally curated results for certain searches. What's being described is personalized curation, at least that's how I read it. I'd definitely be into such a feature, and it really doesn't seem like a tremendous undertaking to make it something opt-in via Labs. I also recall SearchWiki being about specific results, which is not desired behavior for the personal curation experience I have in mind.