If your school is in the mode of teaching you medical school courses anyway, then I don't think it matters much if you have classes together or apart.
If your school doesn't focus much on the medical sciences, then I'm sure many students would suddenly be ticked off to have to learn the additional material if the classes were combined.
For example, I've heard UConn students who are VERY unhappy with the crap they have to learn, which mostly stems from the fact that they are partaking in the med school classes.
We have classes apart because our medical school is in another state, but the way our curriculum is, I have NO doubt that classes would be together if the students were here. At least for the first semester, that is.
Translation: Here at AZ we learn a lot of stuff that probably doesn't directly apply to dentistry, it's good and bad, depending on your mindset. For example, we've had Genetics, Hematology, etc.