Well I'm sure that plenty could be done to improve Twitter, but I'd ask whether app.net does any of those things. Last time I looked it is pretty much exactly the same.
App.net also hasnt been successful enough to attract the majority of people I follow on Twitter. So their value proposition for me looks like this: Im paying for something that looks, functions, and feels like Twitter without the people to follow to create that content.
Build or use your own app without worrying about hitting a token/user limit.
This has pretty much no influence on users. It might slower the innovation a bit, but it's not like there's much innovation happening there to begin with..
This also impacts me as a user because the official Twitter apps have special privileges that third party apps do not. I believe this is why third party apps do not support push notifications.