This infographic (thanks Microsoft!) is a pretty good look at the future challenges.
Other challenges include:
- The sheer scope of the web (it's getting bigger)
- Mobile devices accessing / using search
- Making search relevant locally
- From the IB: Error management
- From the IB: Lack of quality assurance of information uploaded
These standards are used from the IB Computer Science Subject Guide
- Outline future challenges to search engines as the web continues to grow.
- IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.