lucy24 - 9:05 pm on Mar 22, 2013 (gmt 0)
Unanswered question: Is there one underlying index or two?
Look up searches in gwt and you'll find "web" and "mobile" listed separately. At one time there was a further split-- plain mobile vs. "smartphone"-- but now it's just mobile.
Look in logs and you'll find one vanilla googlebot and three mobiles (iPhone, Samsung and DoCoMo). The mobiles only ask for pages, never css or js.
Clearly the information is being collected separately. Is it also being processed separately?