nomis5 - 7:09 am on Dec 4, 2012 (gmt 0)
You don't actually think Matt Cutts or anybody in Google for that matter is going to come out and tell you just how important the whole social thing is to their plan do you?
True, but the opposite may also apply. G would never say that social signals are so conflicting and full of coontradictions that they simply ignore the vast majority of them. Just too difficult to analyse what exactly they mean.
Far easier and more reliable for G to analyse how long people stay on a site, how they move about when on site, if they bookmark it etc etc.