I tried to send this via the Twitter Feedback box, but got a 405 error. Hopefully, it is because so many people are complaining :) So here's my feedback:
New Retweets Are Terrible Because
1) They violate the fundamental rule of the timeline that I only see who I follow. Instead I now see strangers I do not follow, and I see them whether I want to or not. It does this by inverting the relationship to promote the originator of the tweet over the relationship I have with the person I actually follow.
2) They violate the fundamental rule of every tweet being something I compose, since it is impossible to edit them or add comments.
3) They violate the fundamental rule of following that I see every tweet from a person I follow, since the only way to turn off this new retweet from a particular person is to squelch all their retweets.
4) It breaks - and provides no alternative for -the accepted and useful practice of a chain of retweets so we can learn and see intermediate retweeters who may be of interest to us. The fact that someone retweets something can be just as socially useful as knowing who originated it.
Philosophy
Hence, the new retweet privileges the originator and the link itself over the social knowledge gained from the network of relationships.
This is a basic transformation in the structure of Twitter designed to make it easier to identify influencers (of one type) so as to monetize more efficiently, as it is cheaper to influence the influencers than attempt to influence everyone.
And it is a continuation of the old style of centralized knowledge authority which social media are supposed to be moving away from. Hence, I consider it a retrograde step by Twitter. It will privilege the role of key influencers across Twitter, regardless of and without respect for the social networks already build by follower/followee relationship.
Moreover, it goes a long way to erode the neutral stance that Twitter takes towards content types. Before, all tweets were equal, but now the system is designed to privilege a certain kind of tweet and a certain kind of behavior in tweeting.
Let it not be forgotten that the RT was a user community invention and until now, entirely in the hands of users.
Perhaps the best thing for users would be simply to that again: agree on a new convention for rewteeting instead of RT, perhaps IT (interesting tweet) or PT (passing along a tweet) or TT (True Tweet). Or, for that matter, just keep putting in RT the way we always have.
How To Fix This
1) Keep retweets from someone I follow in their timeline, but put a small link below it to original tweeter (viz reverse the way it is now).
2) Add back the ability to edit. Since there will be a link to the original (since you implemented my first suggestion there, didn't you?) the retweet of my direct follower can always be compared to the first tweet of the originator.
3) Where are timeline filters we've been waiting for??? Helloooo?? Anybody home? Development 101 == solve the more general instance instead of the specific one. If you solve the (lack of) filters, then you solve this.
4) Doing 1 and 2 will fix this already with no extra work, but it would be very nice to have representation of the chain somewhere.