Actually this news was firstly reported by 9to5 Mac and according to them More interactive Tweet view experience: content previews, videos, images and more will now be shown within tweets containing links to “partner websites.”
Tweets about “selected events” will now be highlighted. Twitter will curate the relevant tweets and images In the Connect tab, autocomplete improvements will be now be present. Twitter rolled out something similar to their official website last week.
Major push notifications enhancement: You will now be able to choose to receive push notifications when certain people tweet.
Like in Tweetbot, you will now be able to receive unobtrusive Twitter notifications while you are using the app.