One of the very useful things about Moodle has been its simple but elegant distinction between activities and resources. Activities are where the student does something and a record of that student activity is created and archived. A resource is merely a presentation of some type of media or document. The following statement seems to overlook that distinction because a Moodle quiz is a learning activity and not a resource.
"We are, however, planning to create a repository for Moodle-specific resources such as quizzes."
I understand that the goal of MoodleNet is to include non-Moodle-specific resources, but I hope it doesn't blur the very useful distinction that exists in Moodle between resources and activities. The real power of Moodle is the ability to manage student created artifacts in so many different ways. Its what makes Moodle so student-centered compared to some platforms that just present various content to students.