http://www.hsph.harvard.edu/admissions/2012-hsph-statistics/
That's precisely the doubt some of us have. I think that the number of current students' profiles posted on their website is just indicative and definitely not an exhaustive list. THE ARGUMENT: As per the above link, in 2012 they had around 172 SM1+SM2 candidates and so the only questions are ( a ) how many SM1 and SM2, though I believe the number of SM1 students will be quite low because of tougher criteria (say a 30-70 split), and ( b ) the number of students out of these that belong to the various departments (there are 7 of them) at HSPH for SM1 and SM2.
This year, even if they have 120 students for SM2 out of 180 total SM applicants (say), that would mean they have an avg. of ~16-17 SM2 students in each of the departments. This would put an avg. of ~5-6 students each on the three tracks (policy, research & mgmt).
All these, of course, are the ramblings of an overly anxious mind! I would really appreciate any insight from someone who knows about these figures with a considerable degree of confidence.