And finally, the other really important bucket is authority. Google wants to show sites that are popular. If they can show the most popular t-shirt seller to people looking to buy t-shirts online, that’s the site they want to show. So you have to convince Google - send them signals that your site is the most popular site for the kind of t-shirts that you sell.
Over the past few days or so, I have been seeing chatter both at WebmasterWorld and Black Hat World around ranking and traffic changes related to Google organic search. I got to say, I doubt Google pushed anything specific this week or even next week. Rankings do change by itself and new content is always being added to the index but an algorithm update - I doubt it.