obviously, schools (ie columbia) dont ONLY accept 75 students to EXACTLY fill the number of seats, however, the actual number of acceptances given is unknown and therefore i didnt mention those speculated numbers.
i am assuming they give roughly double the amount of seats. that is, columbia in this example would possibly give 150 acceptances and assume that only ~75 of those people will actually attend in 2003. this personal estimate may be too high or low, i dont know, it is only a personal estimate. if i get accepted to 5 schools, i will have to reject 4 of them. i am assuming that there will be many others like me as well. i think that many people (not all) will get accepted to at least 2 schools, if any, and therefore will be forced to turn down one.
i know that last year, university of florida gave approx 30% more acceptances than seats for med school (ie 130 acceptances for 100 seats). 40% declined and they were forced to accept students they previously rejected at the last minute to fill their class. i think that schools (med and dental) will learn from that mistake and offer more acceptances this year, giving our incoming class of 2003 a POSSIBLE advantage. but this is all speculation.
in any case, getting an interview is definately a good sign. your chances have increased from ~ 1/10 to ~ 1/3 or ~1/2. you should also keep in mind that when you interview MIGHT also make a difference. i think that people who interview early might have better chances of getting accepted than those who interview late december. i hope this is not the case, since i personally have a couple of interviews scheduled in december.