Aside from the fact that many DO schools are already listed in US news, I'm not quite sure how many people care about US news and their rankings.
When I applied, my main source of information was the MSAR. Every health professions advisor has this in their office for students to look at, and every MCAT test instructor recommends it to their students. However, the AOA/AACOM or whatever doesn't really have an MSAR-like publication (aside from the website) and if they did, I'm not so sure it would help shed light on osteopathic medicine because only those who know about it would order it (same goes for the website).
How about trying to add DO school information to a publication like the MSAR. I know this sounds crazy, since the Association of American Medical Colleges doesn't recognize [osteopathic] American Medical Colleges. But if you're going to try to expose more students to osteopathic medicine and its schools, I'd start with something like that.
And yes, I realize that the MSAR is published by the AAMC and [currently] only lists LCME accredited institutions including those in Canada and PR. But why should the LCME be exclusive to the American Association of Medical Colleges. They already have sections differentiating Canadian LCME accredited schools from US LCME accredited schools, why can't they just add another section for US AOA accredited institutions and include a blurb describing osteopathic medicine?
Or if that doesn't float your boat, how about an entirely new body that doesn't distinguish between AACOM and AAMC. If they don't want to share information with each other, create a neutral body that will. Then you can replace the current MSAR with one that contains information for both AAMC and AACOM.
If you want people to become aware of two "separate but equal" licenses, put all the information in one place for them. I don't want to go and read two books to find out about things that are basically the same. I also want to read about these things in the same format. I don't want to have to be reading along about allopathic medicine and processing the data for various schools then have to switch to an entirely different format to learn about osteopathic schools. I want the same exact data for both kinds of schools. It may sound minor but when you're looking intensely at statistics and information for 150+ schools it's really nice when everything is the same.
But I digress. So I say again, start by combining all of the data for all of the medical schools, allopathic and osteopathic alike, and put the raw data in a big, well-known, trustworthy [read: not US news] book like the MSAR that most pre-meds will have exposure to. No rankings, just information.