In Matt Cutt's recent Google Webmaster Video he and Danny Sullivan answered the question "What are some search trends on your radar?"
Matt indicated they were:
- Helping hacked sites and adding site hacked notifications to search results
- Communication - How to let people know they have an issue and how to help webmasters with reconsideration requests etc.
- Social data being used in search engines (ie using social signals to rank search results)
- Online merchant reputations used in Google as a ranking signal
Check out the videos!