Google as a general search engine, do you mean? I think Google will remain the primary general search engine for 10+ years. They're embedded. Direct competitor

Google as a general search engine, do you mean? I think Google will remain the primary general search engine for 10+ years. They're embedded. Direct competitors universally follow the pattern of "Copy Google's ideas about search, but with less economic resources". However, I expect more specific, targeted search engines will eat into Google's market. Possibilities are endless and unimaginable: but a current example is Wolfram Alpha. Wolfram Alpha searches displace Google searches.