[note: it appears that you have to be logged in to a gmail account to see these new "features" and that not all accounts have been enabled yet]
Thanks to Steve Burge of alledia.com for alerting me to this. I'm sure as an SEO expert he will be blogging about this in more detail shortly. Update 14:24 - Read Steve's comments here]
Google claim that this is only a personal tool and that
"The changes you make only affect your own searches."
But in the next sentence they state
"You can see how the community has collectively edited the search results by clicking on the "See all notes for this SearchWiki" link."
So which is it google? A public tool or a private and personal tool. You used to have a slogan "do nothing evil" at first glance this tool encourages people to do evil.
I'm sure we will be hearing a lot more about this in the coming days