First, I would like to say this is just a guess by one simple internet user, nothing more. What if google wants to provide results based on google chrome. Google receives every site you visit, how much you stay and more things. Then based on these results it updates the search engine results. We have seen many strange things happen nowadays and it started after google released chrome so maybe they test it now ?
There is belief that Google already uses user data to help rank websites. They already had a lot of stats from people using the Google toolbar. Then they expanded that user data with the introduction of Google Analytics. Next came Google Chrome. Now they are able to track a fairly large percentage or users. I'm not so sure that they definitely use this data for ranking websites though. It is the kind of data that can be artificially manipulated by any good hacker. All it would take is some kind of automated script that clicks on search results from a unique ip each time. I don't think Google trusts us enough to risk that.