The new retweet function on twitter has led to much discussion, but retweeting might clear up a lot of interesting questions on authorship and citation issues.
There have always been several ways to retweet posts, and there was little standard as to how this was done. A forthcoming paper by danah boyd discusses many of the issues of how tweets were passed along and the complications that arose from these methods:
As messages are altered, it can be difficult to discern who is being addressed and who is being cited. Ambiguities abound, both with respect to pronoun usage in the content of messages and in conjunction with the attribution protocols surrounding retweeting. For example, when a message is retweeted, the authorship of the message changes, adding ambiguity to personal pronouns. Who is the “I” in a retweet? Is it the retweeter, or the retweeted?
The new method of retweeting eliminates this and other concerns, such as who gets credit: the last person to retweet or the original author? The goal of the new scheme is not only to eliminate these confusions, but also to reduce retweet spam if 10 of the people you follow all retweet the same thing.
However, the new native retweet system does not allow for comments, which eliminates one of the fundamental reasons for retweeting. The new system keeps the authors straight at the expense of discussion. It seems unlikely that Twitter will add a comment system to retweets, for fear of both losing its simplicity and venturing too far into the direction of Facebook.