Think part of what Zivush is getting as it that in the future it could be difficult in a traditional SEO sense to optimize for search terms like say 'red widgets'. Do you appear #1 or #2? Well with a high degree of personalization (and not just the historical stuff we're seeing now) this could be wildly inconsistent. Maybe google puts you into a 'old person' profile based on your search history and determines old people would be better served by widgetx.com for 'red widgets', while young people would be better served by widgety.com.
Ton of potential with personalization which we're seeing a little with search history and localization, but yeah it will make doing SEO a mess if implemented to a significant factor, because you won't know where you really place in the SERP's and therefore won't know how (at least not easily) to improve such rankings.