This guy seems to forget that the reason Google won was because they actually presented search in a usable, non-intrusive way. They were the first company to do search _well_, providing good, reliable results, and also the first company not to surround their search box with a border full of ads. To me this makes his assertion, > There's no more reason to expect search breakthroughs from Google than there is to expect…
Yahoo's directories were more profitable to it than search and thus search innovations were a threat to existing revenue. (See also: pg's Yahoo article about Yahoo's ad sales)
So innovation in search (and ads) came from outside Yahoo.
Similarly, any innovation that fundamentally threatens Google's ad revenue is unlikely to be pursued by Google itself. So there's no good reason to expect that sort of innovation to come from them.
Hence the example of Siri turning a spoken query into a vocalized answer (whenever it can), rather than a list of links with ads around them.
Though the author is off a bit when they imply there's no room for ads in the process. As most use of Siri still involves looking at the screen, on which it would be trivial to drop a narrow banner ad or promoted link.