Nice article that sheds a bit of light on the thought processes of the "evil genius" behind Googles search policies, and although it was written ten months ago, it even then was hinting that in the future Google might be subverting relevancy for profit, which could be one of the explanations of the Florida update.
Perhaps as Googles search share drops when Yahoo drops Google for Inktomi, and MSN starts its own search engine, they may rethink their stand on optimization, which Brin seems to regard as intrinsically evil. I might even go so far as to say that if Yahoos implementation of Inktomi proves successful, and is done before the IPO, Google might be well advised to reconsider the timing of their IPO.
IMO there is no doubt that there are many sites that unfairly rank highly because of optimization (I can think of a few of my own pages that may not be the best available on the web but still rank #1

) but many more sites rank where they should
because of optimization.
Relevancy is hard to judge by mathmatical analysis, especially when relevancy to the user (which IMO is the only relevancy that should be considered) may well depend on things that are simply not judged by any existing search engine algo.
For instance last week I was looking for an internet router, and my first searches were for terms like internet router comparasions, (which Google used to do a better job on) but as I gained more information, I was no longer looking for sites that compared routers but sites that sold routers and, since I had pretty well determined what I wanted to buy, was now looking for sites that sold what I wanted, had them in stock for shipment, and offered the best price, payment and shipping options. These searches did not display results in order of relevancy for me, since the parameters I was interested in (price, stock situation, shipping and price) simply are not ranked by search engines in the way that I was interested in.
SEO is not dead, despite having received a slap in the face from Google, since in order to deliver that slap Google had to severely degrade the quality of its SERPS.
That fact alone should suffice to prove that SEO is still more helpful than harmful to the search engines, and its time for Mr. Brin to take off his blinders and realize that its impossible to quantify everything as either black or white.