crobb305 - 10:59 pm on Apr 8, 2011 (gmt 0)
I accept SSL certs MAY show an improved trust but the vast majority of web sites use virtual servers on a common IP
Well ranking signals aren't necessarily a function of what the vast majority do. There seem to be plenty of signals in the algorithms that the vast majority of websites/webmasters might not be capable of achieving. I know people who use WYSIWYG websites for their business, with very limited control.
I have SSL and I am still on a shared server. All it took was filling out a 6 or 8 field form requesting SSL and paying $2 extra each month for a dedicated IP. My webhost provides free SSL for their business account holders. Trust signals have to start somewhere, and perhaps you have to be willing to pay $2 a month. I don't expect everyone to be willing/able to do it. The vast majority of websites aren't going to win a Webby Award either, but it was specifically mentioned in the website credibility study.
It's just speculation, as we've been talking about the possible ranking/trust signals for quite a while. This might be a signal (one of many possible signals). I'm not suggesting that it's a make-or-break signal, or that everyone needs to get SSL certified. It's clearly a judgment call. Google wouldn't have TrustRank if there were no trust signals.