Hihi Saladito!
Yes, this is VERY good - Health Management and Policy is the ONLY department at UMich that interviews. Also, when I was there they told me they accept about 85% of those who they interview, so just do well on that and you'll probably get admitted. Be sure to know a few things when you go there - 1) Why do you want to go into public health? 2) Do you prefer management or policy and why? They will definately ask you these things. As of last week, 40 slots of their 75 have been filled, and they are still waiting on responses from another 20-25 or so.
If you want specific details as to what will happen to you during your interview day, post back or PM me and I'll be glad to tell you. Good luck!