Asahameed:
Thank you! I'm greatly looking forward to it!
Now to your questions:
dds2b hit it pretty much right on. They have no cap for foreign or domestic students, meaning: if you have the money, you have the same chances as someone with your credentials who lives in Boston.
With that said, the fact that you've been offered an interview implies that you've got an excellent chance of being accepted! They quoted me that they offered about 80% of the interviewees acceptances. When I interviewed (Feb 21st), they'd already filled up about 107 spots, out of 142. Like one of the previous posters mentioned, your odds are good, unless you have an absolutely horrible interview.
My interview consisted of a "double" interview, whereby I was interviewed with a professor AND a student at the same time. The questions from the professor were more laid back, but the ones from the student weren't as nice (as one would expect). I was asked the following questions:
"Tell me about yourself"
"Why did you pick Tufts"
"Where else did you interview, and what were your impressions?" (This is an illegal question, so be really careful how you answer it!).
"What kind of extracurriculars do you enjoy?"
"What do you do when you are stressed out?"
"If you could be someone famous, who would it be?"
"Assume you're in a group of six working on your gross anatomy lab, what would you do if someone wasn't pulling their weight?"
Just stay cool, calm, and relaxed, and you should do really well. Also, be sure to ask Mark Gonthier (or whoever is leading your tour) any questions, as he seems to know A LOT!
In all, I think you'll have no real problems getting in (as long as they aren't filled up, and they'll tell you how many have been accepted!).
Good luck and tell us how it went!
Dante.