I read something about how the number of applicants this year is down, and that the application to acceptance ration is somewhere around 2:1. I think it was on Newsweek Online or the CNN website - if you have time you might want to see if you can find te article. Hope that helps!
That question is hard to answer. While roughly half of the people who apply get accepted, that doesn't take into account the premeds who ultimately didn't apply because their #s weren't good enough, or who dropped out along the way. I've notice that there are always more freshmen premeds than sophmores, sophmores than juniors, etc.