What is google wiki search?
It's the new service of google that let's you adapt the search engine response pages (SERP) to what you like.
What does it mean?
It means you can change the ranking of the websites in google according to your wishes.
For exemple, you type in "bar", but you don't like the first answer of google, but you like very much the 7th one (which is a very cool bar), so you can delete the first one, and put the 7th on top of the google results!
How google wiki search is going to change your search engine optimization?
Think as a search engine (as always). What if 1000 people change this 7th answer to put it first, you would probably consider that "yes", maybe this 7th website should be first... and you would change the natural response for every one. Well, i think it's exactly what google is starting doing. They found a way to make people improve their search engine and work for them... for free!
Back to the Content is King :
It's gonna give more power to your content. You probably, like me, fall sometimes on websites that do not respond to your query, but that are first because they optimize the web page to be first. well, now you can delete them, and google will know it.
If you don't want your website to be deleted... well, better provide the right information to the right query then.
Google is getting better, what about your own website? ;o)