The descriptions so far are spot on. They're private forums for the schools to use as they want. They issue the password to people they choose. The thing to remember is that they will use the private forums how they want, some might put up all their info in there and some might just have informal chats about coming courses or past ones. I expect that they'll grow into a wide range of things.
It's a great place to put central information, if there's last minute course info etc, people can just have quick look and it only has to be posted once.
There's quite a few schools interested in having the forums but i'm not sure if they're going to invite people as they come on courses etc or mail their whole lists and let them in, we'll have to wait and see.