I have some ideas about conditional activities and I'd like to know what you think (as it may change the way I'm trying to code things).
multiple instances of 'pathways'
for one course, a set of ressources can be organized in different ways, allowing the teacher to have, for instance, a "discovery pathway" with a lot of ressources for each "node" and a "expert pathway" with less intermediate nodes.
full-ranged combination of conditions
One approach to combine predecessors of an activity is to use 'AND' : A AND B AND C must be done for D to be available. For instance 'OR' could be used sometimes when you want to state the activity D available if a student has done one of 3 similar activities.
conditions on many fields
This feature is a my 'most wanted' one, as it may allow prerequisite to be computed not only upon some fields like : 'activity has been seen' or 'activity has been scored more than N' ;
but also upon fields like : 'current time is more than' or 'other users on my group have scored more than' or 'this quizz has been attempted 3 times', 'this student has bad marks in this category of questions' etc etc
notifications
if a student is "trapped" in a loop inside the pathway (or any other painful situation), the teacher gets a notification (don't know how, maybe in logs or private messages) and then the teacher can help this student solving its problem (or leave him in the trap, depends on teacher's relationship with this student
advice or order
two modes available : either everything is locked (order) until completion, either everything is available but some activities are highlighted (advice), allowing the student to see what activities are best suited for his "profile" (or "level")
I'm sure you all have many more ideas, and this post might be a good starting point for sharing them or preparing a brainstorming as Bernard suggested.
(this month I'm trying to code the multiple instances feature...)