What can Twitter do to maintain their value? Right now, anyone can duplicate Twitter's functionality (i.e. App.net). Myspace lost because Facebook did everything better. Because Facebook continued to innovate, it would be hard to replace. Twitter on the other hand, hasn't done much that's irreplaceable.
I think Twitter's move to remove the "Find my friends" feature is because they're scared you'll move the conversation elsewhere. Just look at what I'm doing here with Branch.