There are a lot of companies using infinite-scroll, I'm talking about data-driven companies that are fighting for user engagement (Facebook, Twitter, Tubmlr, etc), although most of the media/publishing outlets aren't in that group some newer (redesigned) sites are doing it too, see ReadWrite, BuzzFeed and Quartz.
The problem as I see it is that the traditional web design assumes that there has to be a footer, but if you design with the infinite-scroll in mind some interesting solutions appear: see how ReadWrite cross-promotes the other sites at the end of the sidebar, as well as places the footer links in that section. (This is actually how it should be done, rather than putting the users that want to click the footer to chase it between scrolls)
I don't think that there are any studies, I've done some research previously, but if you think about it, at least in my personal scenario, the >80%-90% of the times I get to the footer is not to click footer links, it's to click the load more button.
So that is a valid study that you could easily do (and tell us ;) ): what percentage of clicks goes to the "Load more" vs the rest, that can give you an idea of how important for your audience could be to save them that click.