How to engage students in oral presentations?
I would like to add to earthling's answer. If you have teaching assistants, please do make good use of them in this aspect. 

As a TA, I have had excellent experiences in mentoring undergraduates to prepare research presentations, final papers, projects and proposals for these papers and project. Of course, we were generally in a class of 120-160 students so that speaks to a classroom scale higher than what you are suggesting. There were 3 graduate TA's, usually and we each had about 50 students to mentor. We found that we could devote significant amounts of time to each student when we met them on a one-on-one basis. Of course, the professor also met them one-on-one and there were a couple of rounds of iteration of their final presentations - which was very, very useful for the professors, the TA's and the students. As mentioned previously, it was a time sink, but very well worth it.