1) Exact string matching. As an example, if I search for " 'x.25' " don't give me hits for something with dimensions of 45mm x 25mm.
2) Allow more complex search constructs . For example I'd like to be able to specify the search term " 'x.25' near protocol -handbook ". You can sort of do that with Google's Advanced Search, but it's extra steps and you still don't get terms like 'near' or exact match.
3) Bonus points for boolean constructs such as " (lions or tigers or bears) near woods ".
In short, provide a robust search engine that will support meaningful search terms that can be used for more than shopping for a new TV or figuring out who stars in your favorite reality tv show.