If you're website has recently lost trust and or rankings in Google vote to have Matt Cutts tell you what is going on here - http://goo.gl/mod/oEca and here http://goo.gl/mod/f43P
I think there are a lot of factors that go into rankings that you can't necessarily attribute it to a specific change Google has made to its algorithm. Markets, Keywords, Competition all change on a daily basis. All you can do is continue to research, perform good SEO practices, and build backlinks on a daily basis. Interesting link though.
I think you're confused this is specific to what is going on recently with Google and has nothing to do with everyday SEO.