As far as I am aware the entries in the G SERPS are exactly the same when viewed from a desktop as when viewed from a mobile. In essence, G has no mobile SERPS.
The question I have been asking myself, with the increase in mobile usage, has to do with responsive design or a separate mobile version of a site. Let's stick with the more common solution, responsive design. Let's say for instance that my main menu on the full site is too big for the mobile version, so on the mobile version I miss out the link in the main menu to red widgets.
If a user searches for red widgets on G, using a mobile phone, the mobile G results will show my red widget page purely based on the pagers / links in the main site. The fact that my mobile, responsive design version of the site, has no link to the red widget page is ignored by G. That appears to be wrong to me and I can't get my head around how G will ever solve the problem unless they introduce spearate SERPS for mobile sites. And in truth, that appears, to me, to be several years away.
Any thoughts, it may just affect how we design our sites for mobile usage?