deadsea - 11:51 pm on Sep 1, 2011 (gmt 0)
Google's "long click" is a major part of their algorithm. If folks click on your site and are satisfied (don't come back to the SERPs and click on other sites, and don't refine their search) then your page will rise from 10 to the top 3 very quickly. If you are in the top and Google sees user unhappiness, your page will drop like a rock for that query.
I don't believe that page speed itself is a major component of the Google algorithm, but the effect that it can have on the long click can be horrific.