Wissam Dandan posted a screen shot of a Google Mobile test on Google+.
The test is where Google is placing a "Quick View" button, a very large one, in blue, in the mobile smartphone search result. If you click on that button, it will load a mobile preview of the site. I was not able to replicate it myself but here are pictures from Wissam.
The search result:
The landing page:
Now, I have a few questions out to Google on this. They did confirm this is a test but I wanted to know two more things:
(1) Does the quick view landing page render a pre-fetched version hosted on Google's servers
(2) If not, is it loading a mobile version of the web site on the source's server?
(3) How do sites get picked up to be granted one of those "Quick View" buttons in the mobile results?
I hope Google responds to those queries and I'll update you with anything relevant when they do.
Forum discussion at Google+.