lucy24 - 10:26 pm on Nov 14, 2012 (gmt 0)
Hypothethis: It has nothing to do with whether the site is any good for mobiles. It's based entirely on what googlebot-mobile sees. If it's redirected (based on UA or some other criterion) to a mobile version of the site, that's what the SERP shows. If it gets the same page as everyone else, it's same old same old.