Thank for the information, that was both helpful and informative.
Now I'm ignorant about the development model. I'm considering whether it is worth moving to the trunk before our term starts (first day of classes here is 9/27.
I'll happily hear opinions on the following: given that we are using 2.4.7, how likely are we to experience breakage of some kind (including with homework problems) moving to the trunk? Are other big installations (we'll have something like 50-60 courses this term and about 2000 students) using the trunk happily and stably?