I always had an inkling for a Search Engine that ONLY indexed the root page of every domain. Not sure if I'm right about this, but it sure would sort the chaff from the wheat for general purpose queries.
Seems like that would just give you all those made-for-seo sites that tend to have second-rate content at best. ie, you search for 'best electric lawn mower', and you'll get bestelectriclawnmowers.com, 10bestelectricmowers.com, etc. Those sort of sites exist for every imaginable topic, and in my experience are rarely worth visiting.
I would almost want the opposite. The best content on most topics I've found tends to be a page on a discussion forum of some sort, followed by blogs and more general editorial sites.
What we really want is a system that classifies your query as being one of "forum/blog/shopping" and then makes a scan only over that class of pages.
So on launch-day you would have checkboxes. On the one-year anniversary you´d have those checkboxes removed.
Google probably implemented this a couple of decades ago, though, so what we _really_ need is someone to come up with a new business model more attractive than Google's.
I would almost want the opposite. The best content on most topics I've found tends to be a page on a discussion forum of some sort, followed by blogs and more general editorial sites.