Here's a great overview of the debate:
http://openpresswire.com/twitter/ret...edia-citizens/
My commentary: If Twitter were a forum, I'd agree with the thesis that Retweeting is stupid. A Retweet would be like a 1 smiley emoticon response at a forum. However, Twitter is NOT a forum, it's a set of interconnected circles of influence. People in your circle might not be on the list of people you follow. If you retweet someone's update, you are effectively broadening their circle of influence. Very powerful stuff. Adapting Al Capone's voter awareness message--retweet early, retweet often.
Incidentally,
Twitter changed their @ settings due to technical considerations.