1- Some webmasters believe this is about Google promoting Android flavored web design over ios/safari design.
I'm not sure how the majority of the world using Twitter Bootstrap or Wordpress w/Bootstap or some other RWD is Android specific as it works just fine in both platforms. The crawler has no clue what browser is accessing that site, only that the site is mobile ready. Even if the site had lot's of Safari specifics in it, the traffic to that site could be 90% Android, there's no way a crawler alone can tell the difference. Mix it with Google Analytics, or AdSense stats, or even downloads of jQuery from Google's CDN and then you've got actionable intelligence that could be used to rank Android sites higher.
I'm betting these same people also speculate Google got this technology from Aliens, and it was handed down after being stored for millennium in a newly discovered pyramid, inside the arc of the covenant, and has been protected all these years by the Knights Templar who used this technology to originally start Motorola which is why Google bought it's mobile arm to gain access to this ancient alien technology. Am I right, getting close?
They're also probably promoting all stories about Elvis to the top of the index as he's supposed to return next summer on the mothership, so they have to get the SERPs ready in advance.
The reality is the mobile world is split into basically 4 parts, Android, iOS, Windows, and what's left of Crackberry.
Therefore, to say Google's push to go mobile has Android overtones is obvious because it's the dominant mobile OS last I checked so whether it was Android or iOS that was dominant, it would be suicidal not to pay special attention to the leading mobile OS and give Bing an edge. Not that they can really pick Andoid oriented sites, other than sites with the word ANDROID in them, as that's the only real clue IMO.
I think the word we're looking for here is "DUH".
However, there's nothing special about RWD sites that run on iOS either, so how can such ridiculous claims be made?