I'm sure it's been done before. A few people each year at DMU probably transfer from DPM to DO program after first year of pod school also. People also apply to say, both MichSt's MD and DO programs. Applying to a school's MD and DPM program or DO and DPM is basically the same thing.
The majority of current pod students have applied to MD, DO, or DDS in the past. Also, most accepted MD students probably applied to other programs as backups unless they had numbers so high the only question was where they were getting in, not "if."
It might raise a quick question at the interview if you're interviewed by someone who is on faculty or an admin for both programs, but it shouldn't be a problem. Just tell Temple MD that podiatry is interesting and it's your backup. Tell the pod school that you are interested in diabetes and ortho and would like to treat them whether it's by the MD or DPM route... "after all, health care professionals are a team that works for the patient."