I had my interview on the second day, so I know exactly what you mean, verbal_kint. I can't stand the waiting anymore! We are indeed supposed to find out next week. Hopefully they'll have mercy on us and let us know at the beginning of the week rather than at the end.
As far as my interview went, I too had to stop myself from replaying it over and over in my head, wondering what I could've or should've said differently. I didn't have anything that I was truly "stumped" on; most of the questions were ones that I had anticipated (about my research, about my decision to go into vet vs. human med, about some undergrad experiences, a few ethical ones about the cities wanting to ban pit bulls, what to do with dog maulings, and how to deal with lab animals/animals of ppl who can't pay). I think the "worst" question, at least the one that I kept thinking about afterwards, was "convince me that you deserve/want to be here". Not that I wasn't expecting it, exactly, but that I couldn't stop thinking "oh lord, did I really convince them?" afterwards. I hope I did.
Good luck to you all! Now back to trying to concentrate on work for awhile...I so wish I was in school right now, it makes the time pass so much faster!!