If you are using groups to separate multiple sections of a course, you can easily wind up with several hundred students. It would be nice to have a search box to assist you in the process of manually assigning participants to the proper group. In addition, it is pretty horrible to have the students displayed by first names when all of our rosters are formatted lastname, firstname. I recognize that this is not a universal problem, but certainly is for all schools in the USA.
http://moodle.org/mod/forum/discuss.php?d=76799 (discussion about need for search box)