If recent indications are anything, then personalization is still the one to watch heading into 2010. In a recent poll in the Dojo, (public) more than 40% of the respondents believed that it will have the greatest impact on the (near) future of SEO.
It broke down like this;
Which do you feel will have the greatest impact on the future of SEO?
Considering the poll is a week old, they just might have been onto something with the recent launch of Google Social Search (in Labs) which is most certainly a new level of personalization. We put that with other explicit signal gathering, there is a strong interest in behavioural data.
Beyond that, social search itself comes in at #3. At the number 2 position is another area that is ever increasing; Geo/Local. It has become more and more common to end up