Not sure I would go anywhere near this far (Google being irrelevant) since Google isn't sitting still. CEO of uber agency WPP just mentioned his company increased their Google spend 17% while flattening out Facebook a week ago on @Squawkbox. That said, I do see incursion being made by mobile search, video and social search. The Google castle is in need of defending.
From The Article: "Google’s search marketing services may be becoming irrelevant due to the rise of social search.
That’s in addition to a failure to recognize that Google+ cannot be the sole solution to social search with an always increasing number of web properties.
Info-Tech Research Group expects that Google, which held 90% of the search market in 2010, will only hold 30% in 2013, due to the rising impact of social search".
Via Antonino Militello