tedster - 4:56 am on Mar 24, 2012 (gmt 0)
The total algorithm is signals PLUS the way those signals are combined and interact. What I currently feel is that not even Amit can say exactly how the signals combine at any moment, or what the end effect in any particular moment will be - especially in a given SERP. In the past year, I've heard Matt Cutts respond to certain observations by saying he would look into it, or that it wasn't intended and he'd like some examples of such and such so they can research it.
I certainly think Amit knows (really, any Google search engineer would) which signals are currently used and which are not.
They would also know the potential signals - the ones where data is being collected but not currently used.