mmm Do you need it in Moodle? No, I don't think so, but a failure of vision on my part does not mean to say it is not a good idea.
In Moodle you can set the commencement and closure dates of all courses in settings, one setting. You can turn on or off the visibilty of any resource, any activity, any quiz, any forum, any assignment, at whim. You can hide entire courses or one element, all in the blink of an eye. You can choose to not use dates at all, I actually rarely do in my courses, but I am constrained to a particular pattern of week blocks in courses depending on theme and topic. Forensics is 8 weeks, but genetics, physics and chem were 10 weeks each. Trig was supposed to be 4 weeks, but I took 5 by adding an additional set of navigation and engineering modules. To offset that, I then took 2 weeks to do a 3 week ratio and scales theme. If you want, in Moodle 2, you can set pathways by ensuring that an activity is completed to a satisfactory level before moving to the next activity. You can set up the progress through an entire course by using these conditional activities.So I am not sure such a mechanisn is required, just seems to me to be a little piece of bling to add to the bloated corpse of WebCT. (Yes, I have used WebCT, and I saw its potential, then I saw its potential just drain away over the last few years. Pity, but it is just business.)