I went back to read previous posts on this topic but I think there's always more to say.
One thought goes that the medical model is about diagnosing disease processes/injuries and to treat that disease/injury whereas the nursing model is about helping a patient deal both physically and emotionally with the illness process. Since both medicine and nursing currently take part in preventative health care, perhaps we should develop a whole other discipline for that, and, in fact, that may happen eventually....
Anyway, the NP role, by those definitions, IS medical in most cases. They may be more aware of the nursing needs of the patient (assistance with ADLs, preventing skin breakdown, psychosocial support, etc), but their main practice would be medical (diagnosing and prescribing treatment).
Just tossing thoughts around...