Google is now displaying Google+ logos and icons for the company profiles in rich snippets portion of search results.
The Google+ icon is displayed next to the search results for the company and Rel=publisher markup is also not required to show up the logo of the company. Assumptions are around that a company needs to have Google+ page and a verified website in the Google+ profile.
Notice the Google+ logo for travelstart.co.za in Google South Africa results.
Travelstart doesn't have a rel=publisher markup code on the home page. And there's no schema on the page. However, the Google+ profile page of the company has a verified website listing.
It was just two months ago, Google said that publishership will not be coming anytime soon and it has no plans to bring it to search results.
Here's Google.com result for Phoenix East Aviation
Although Phoenix East Aviation has rel=publisher markup on the page but they also have a verified website in the Google+ profile.
If Google search results have already adapted to the trend, you will see more usage of rel=publisher markup and businesses & nonprofit organizations adopting Google+.Google Showing Google+ Logos of Companies in Search Results with & Without Rel=Publisher!,