Google Accessible Web Search

Google has launched an accessible web search engine that ranks websites depending on how accessible they are thought to be by Google's ranking algorithm.

So websites that have clean semantic code and degrade gracefully in terms of switching images off are rewarded with higher rankings.

What I'm wondering is that if Google has this algorithm to rank accessible sites does it gives us a little clue that perhaps this algorithm or at least similar elements from it could be used in the normal Google algorithm. I think it's enough of a clue to add to the business case of developing accessible websites. Potentially from a reverse engineering point of view a more accessible website might be considered by Google to be a better source than another website that isn't accessible and for that reason rewarded with a higher ranking.