Of course, there's no way to definitively say one way or the other whether it's being used to influence the SERPs (I happen to believe it is as I don't think G would put so much time and effort into it without using it), but it is being seen in the SERPs more and more. See what they're saying at Pubcon. Yesterday's preso [pubcon.com] by Greg Boser (former WebmasterWorld admin WebGuerrilla [webmasterworld.com]) has this takeaway:
This means that links on the Web will be weighted more by WHO the link comes from rather than WHERE the link comes from. A link from Mashable is great…but it now matters who wrote the piece. Putting it into search times, Greg says that a link from Danny Sullivan on Search Engine Land is going to be worth more than a link from Barry Schwartz because Danny has a greater circle.