I can say with certainty that getting an MPH will most certainly NOT be looked upon unfavorably, assuming you do well. Just as a side note, not all MPH progrmas are two years in length - some are 1 year depending upon prior professional experience.
The degree I will receive in May will be an MHA, but it inclusive and then some of the course work that a typical MPH encompasses.
My MHA allowed me to get great grades in a tough program - this made my so-so undergrad grades pale. Admissions commitees have apparently weighted them very heavily. I have been accepted at 4 schools thus far.
I know 3 folks off the top of my head that got Public health degrees and are now in med school. It really lets you converse about health care matters very easily. This helps a ton in interviews. I definitely had a HUGE edge when it came to the interviews. Soemthing like the prospective versus retrospective cost reimbursement system is old hat to me, but might as well be like chinese arithmetic to other interviewees.
All in all, I am glad I decided to pursue an MHA. I don't think I would have gotten in with a mediocre undergrad record, okay MCATS, lots of volunteer experience and years as a paramedic.
It also lets you get GREAT recommendations if u choose to get after it.