First of all, congratulations on the interviews everyone! If your interview was like mine, there will be three different styles within the interview day: a group project, MMI, and two one-on-one interviews. You show up, get your grub, and get assigned to a group. They are going to explain everything about the school, and then you will split off and some will be doing the group project, some will be doing the MMI, and others will be doing the interviews (it's a rotation).
Now, what's new for you beautiful people is you have A) an actual building to tour, and B) The inaugural class to answer questions. I don't know how that will fit in with the interview day, but it definitely will somehow.
As far as tips go I would definitely look up MMI format and understand what it is. Also, just be cool and try to have fun. I know that's kinda cliche, but if there are any specific questions I'd be glad to answer if I can.