I'm realizing in talking to other international students that not all of them know what they'll be taking next semester. "Yeah, I didn't get all the classes I wanted; I'll have to figure it out during Add/drop," is a surprisingly common refrain.
I used to think BU was silly for making us sign up for all our courses for the whole year in the summer before. But on retrospect, I'm grateful. We're not completely locked into anything, of course, but it still allows us more certainty than having to scramble around in the fall would. It's the best of both worlds, actually: flexibility and predictability.
* I'm now 98% decided that I will take Criminal Procedure instead of Trial Advocacy. It will certainly be much harder, and it will mean that I'll have FOUR EXAMS(!) at the end of the semester, but I think it will be better in the long run for the breadth of my education.