I have a lot of friends and when I update my home page I see a few hundreds of new entries in my stream. Of course I have no time or inclination to read all this. If my friends post something interesting in their streams, it gets lost in all this flood of notifications about the lessons done and discussions answered. The same thing makes it useless to share my own thoughts in the stream: nobody will read them.
It would be cool to have different tabs inside stream: Posts, Discussions and Progress.
You're right, the stream can get cluttered. You've previously suggested to give users filter options similar to those for e-mail notifications, haven't you? Would you like to see both those ideas implemented or do you see this more as an evolution of your previous suggestion?
This is rather an evolution of my previous suggestion. I suggested to make a filter in Settings, but Settings are a little far away while a filter in the Stream itself would be more user-friendly and intuitive.
A similar system is used on another favorite site of mine - klavogonki.ru. It is a typeracing site. There is a kind of stream, too, that includes users' posts and auto-posts about their new records. There is an option to view posts only, records only or both sorted by time. As a result, some users use their stream as a blog that is easy to read. I'd like to see such blog-like streams here, too, but the current conditions are not very favorable for their appearance.
Yes, my friends seem very "third person" right now with the constant "kaicce did five lessons...kaicce translated 3 sentences". As much as I like details, it does not really provide a social environment. These ideas should be implemented in place to make room for learner interaction.