Google's biggest challenge right now is Staying Relevant

Out of 20,000 potential matches on YouTube, out of 21 million potential video matches across the web, what does Google’s supposedly sophisticated Universal Search algorithm pick out to display as the top video content to be shown within the top search results?

A cartoon created by a company pitching its SEO software on YouTube as a way for Santorum to solve his Google problem. Wow.

Relevancy took Google to the top, Relevancy (or the lack of it) will take it down.