I'm not quite sure about that. Check this part: "More specifically, developers ask us if they should build client apps that mimic or reproduce the mainstream T

I'm not quite sure about that. Check this part: "More specifically, developers ask us if they should build client apps that mimic or reproduce the mainstream Twitter consumer client experience. The answer is no. If you are an existing developer of client apps, you can continue to serve your user base, but we will be holding you to high standards to ensure you do not violate users’ privacy, that you provide consistency in the user experience, and that you rigorously adhere to all areas of our Terms of Service" This sounds to me like they don't really want "normal" Twitter apps anymore, but have just grand-fathered in the existing ones, while opening the door to closing them down if they don't follow the guidelines.