One bad thing about Facebook ticker is that it shows the kind of activity which not all users would like to publicize. For instance, I just checked out on which communities/pages my friend commented. The Ticker even showed the text of his comments. This streaming will perhaps continue to show to all friends. I think its not good for ones privacy. Personally i do not want people to see on which pages i go and what contributions i make.
Similarly the app is displaying what comments you would make to the photos of your friends and families. This is very bad.
One good thing about this feature is that it rotates the posts/updates by friends and the pages you have joined.
I think Ticker must not go ahead of it and shall only limit showing only the posts/statuses activity.