Although I might be in the minority with the blogging community, I think that the Associated Press is right to speak up about all the lower-quality blogs that simply cut and paste their articles. Simply re-reporting the news clogs up the internet without adding meaningful content. However, I don't think that AP's plan to set standards is necessarily the answer. If it does so and then fails to enforce them, it will lose credibility.
Those who post blogs should make use of links and quote news articles appropriately. Longer quotes are necessary in order to fully respond to the article's points. However, there are blogs that are really just plagiarizing the news by re-wording it or outright reproducing it without adding meaningful analysis or commentary. That is not fair use, but infringement.