Peter B. Ajluni of the AOA in 2008: "Since physicians are likely to practice within the area where they received their training, new colleges of osteopathic medicine are being established in some of the nation's most medically underserved regions, including New York City's Harlem community, which welcomed its inaugural class of osteopathic medical students last fall. As the osteopathic medical community looks toward future growth, it will continue to honor its tradition of producing primary care physicians to ensure that all people have access to health care. "
I think this is a wonderful goal, and opening up a DO school in a rural area IS a great way to get MORE primary care physicians into needed areas, but this in no way forces students into primary care. Think about it this way ...
Say an area has 2% primary care physicians, a DO school opens in the area and 35% of it's class enters primary care, and of that 10% of that class stay in the area. This greatly increases the needed amount of primary care physicians in the rural community, but in no way indicates that the majority if the class entered primary care, nor that the majority that did stayed in said area. The goal was still achieved, but by no means was the class 100% rural FM.
Also, just some more facts:
- In 1960, there were 13,708 physicians who were graduates of the 5 osteopathic medical schools.
- In 2002, there were 49,210 physicians from 19 osteopathic schools.
- Between 1980 and 2005, the number of osteopathic graduates per year increased over 250 percent from about 1,000 to 2,800. This number is expected to approach 5,000 by 2015.[16]
- In 2007, there were 25 colleges of osteopathic medicine in 28 locations.[17] One in five medical students in the United States is enrolled in an osteopathic medical school.[18]
- By 2020, the number of osteopathic physicians will grow to 95,400, say expert predictions, according to the American Medical Association.[19]
-AMA says 95,400 by 2020 and the numbers show a huge increase in the last few decades.
-There is also no doubt some areas will also have more DOs than others (some go as high as 15-25%, others as low as 1-2%).
-Wikipedia (lol) also says that 51% entered MD residencies in 04, 46% in DO.
-Primary care:
Osteopathic physicians have historically entered
primary care fields at a higher rate than their MD counterparts. Some osteopathic organizations make claims to a greater emphasis on the importance of primary care within osteopathic medicine. However, the proportion of osteopathic students choosing primary care fields, like that of their MD peers, is declining.
[49] Currently, only one in five osteopathic medical students enters a
family medicine residency (the largest primary care field).
[50] In 2004, only 32% of osteopathic seniors planned careers in any primary care field; this percentage was down from a peak in 1996 of more than 50%.
[48]
Also, I'm just curious, where are you getting your numbers from for total # of practicing physicians in 2020? I found a few different numbers while searching around, but too much variation.
Finally, there is a chart floating around SDN with % of DO students entering primary care fields broken down by school. Some schools have as low as 25-30% and others (such as WVCOM, ranked top in primary care) has up to 80%.
They think it is the most dangerous thing to ever do on a patient. Another reason why they just don't know what a good COMLEX score is and ask me year after year when applications come rolling in and we all sit down to choose applicants. 
