trakkerguy - 3:43 am on May 17, 2010 (gmt 0)
If it is CTR (or even Site Performance)
don't you think that if this was being taken into account then they would want to release that information
As soon as they (google) confirm site performance influences serps, webmasters will be trying to fake stickiness, or traffic, or whatever they think google is measuring.
I'm not saying they don't/won't use visitor behavior, but just don't see them being too forthcoming about it.