As usual, I get this features on testing account, not mine main one.
You can turn on/off seeing retweets for any user you follow.
New button and confirmation dialog.
Retweeted tweet (
http://twitter.com/madciapka/status/5570081490)- as you can see, it can be "undone".
The same tweet seen publicly - no sign of retweet.
This is how it's shown in the timeline of the user, who retweeted the post and while logged in with "retweet enabled" account.
This is how it looks like for anyone else and the public (
http://twitter.com/twistedf/status/5602048422)
