I thought this was going to be a post about the treatment of diabetic ketoacidosis when I clicked on it, but alas, no...
You folks are forgetting one factor - calculation of GPA. AMCAS has a different formula and includes more sciences in the science GPA, and also does not replace grades for classes that are retaken. Also, a 3.8 from Penn is not the same thing as a 3.8 from Penn State. People are already stratified in high school, and the cream of that crop tends to head to better schools like Penn. Better medical schools will often have students from better undergrad schools. The pedigree of students at Penn Med, for example, is a lot better Temple, is a lot better than Philadelphia Osteopathic. Take that how you will, but it is a fact. As for people going into competitive fields, say, radiology - it is a lot more meaningful to get a residency at HUP than it is at some random community hospital. Plus, if you want to go into academics or ascend the ranks of ivory towers, you really need to train at a powerhouse. The gap is still there.
The residency selection process still has not liberalized yet. It's reasonable to look at internal medicine programs since they have large #s of people and interview a lot, and a field that a lot of DO's tend to go into. Unless we see some New York osteopathic grads at Cornell or Columbia for IM, or Philadelphia Osteopathic grads at Penn IM, I don't think the gap will be closed.