In the long term, when there is a really large mass of data out there, with deep interconnections, then there is some really exciting work to be done on automatic algorithms to make multi-level searches.
And there still is. Some of my bets would be on semantic (ontology identification and interaction), multilingual/multicultural (IMHO huge), local-machine personalized, further processing integration (local or cloud: visualization / result manipulation / statistics / monitoring), reputation and other metric system integration for result entities.