I’ve just been reading an interview with Colly Myers of British-based AQA in the Register. He argues that Google and other generic search engines are beginning to suffer from entropy – the system is too big and polluted by ever-increasing junk links. And Wikipedia with its, um, unique take on research.
Instead, services like AQA provide properly researched answers (at £1 a shot), and actually pay the people who do the research. Alternatively, the users who have grown up with the web are turning to their own communities for answers – currently MySpace or YouTube: as can be demonstrated by a spike in Google traffic when MySpace went down recently
Implications? I would guess the Semantic Web would suffer from the same problem.
Also, it seems likely that topic and portal-oriented search engines like the InQuira system I talked about earlier will come into their own, because they have been designed to control entropy from the beginning.