I've always been skeptical of Retweeting. As the article mentions, it's responsible for diluting the quality of your news stream. Any value-add from the sentiment of a Retweet is offset by the sheer noise-to-signal ratio and redundancy from repetition.

The new feature is a step forward. It seems that it formalizes the Retweet syntax into, what is essentially, a vote for a Tweet. This is primarily what Retweeting has come to mean anyway.

I hope this encourages more original content on Twitter.