Was replying to Slade's post.
No, it is not expected that you have published and been active in extracurriculars during medical school. In fact, it's pretty hard to get published during med school unless you have taken extra time/electives to establish a project, or are on the MD/Ph.D track. If someone is willing to add you on as a second/third author on a publication because you did some work, then great, but a first author publication is not easy to come by in med school with all the time you have to devote to book learnin' and clinical rotations during four years. In fact, many folks don't get to do any research time till 4th year when your apps are already in.
It's nice to have done some sort of extracurricular/community service, but its not expected that you are as active in med school as you were in college. There's just not time. I for example, coordinated the med stud Ronald McDonald House family food delivery program for two years, and did a semester long research project and presented a poster at a med school symposium fourth year. But that was it.
The key is to perform well in class and even more, in your clinical rotations and get great letters. This is the crux of the residency application, along with USMLE scores. If you bring other stuff to the table, great, but average/poor showings in the third year can't be compensated for by research and extracurriculars.