I love RE's potential because it can solve all the problems with newRT and oldRT, and opens up some new possibilities as well:
about 2 hours ago from Twitter Retweeted by 3 stoweboyd: I disagree with @gregarious about daylight savings time themaria: he sleeps all day anyway brianthatcher: I never come out in the light of day
Note that the target of an RE doesn't have to be a tweet; it can be any URL. So RE can also reach outside the Twitterverse and unify all sorts of threaded conversations. In particular, if the target of an RE were Salmon-enabled, a tool could trivially send a salmon representing the RE back to the source -- allowing for truly distributed conversations that retain threading, authorship, and provenance.
The only problem with RE at the moment is that it turns the target into an opaque URL, which looks ugly in today's clients. This can be solved, as shown above, with smarter RE-aware clients. It's not a huge amount of work either -- and the payoff is that you can have your newRT collapsed/summarized view and still have conversations. And even better, they can be open and distributed beyond just Twitter.