An extremely important (in my view) analysis of the so-called 'MayDay update' by Shaun (Hobo) - looks at an example of a long tail keyword that is still at #1 but has lost 87.5% of its traffic since the 'update'!  Is Google's new SERP layout getting people to click more on PPC ads? Are universal search results grabbing more and more space above the fold so a #1 ranking means less? How do our strategies need to change as a result of this? These are crucial questions for forward thinking SEOs to ask and answer.