My final 2 years were similar to tussy's with oral, MCQ and OSCE exams during 3rd year. 4th year was pretty much exam free except for Psychiatry; some rotations required a short paper (except Psychiatry which required 2 long papers. Ugh...) or a presentation on a topic of my choice.
Grading will vary from school to school but is generally based on subjective evaluations as well as your clerkship exam score. Honors may require some additional work, a paper or presentation at some places, or may just be based on your wonderfulness at others.
We still had lectures, although not nearly as many as during the first two years and we were expected to attend Grand Rounds and other conferences. You are expected to read about your patients and the field at large - so don't think you can give up studying! The hours were much longer than in the first two years but *in general* more enjoyable and at times, much scarier (as you realize how close you are getting to being a doctor and how little you really know).
Hope this helps!