While it is great that a series of other public interest groups such as MoveOn are running anti-Bush ads, I do think there is a danger in all these disparate ads could dilute and distract from Kerry's central message (which, as Kos pointed out earlier, may not be as crystal clear as one would like.)
Bush is a terrible communicator, but he and his team always stay on message. That is why their message (however weak) sticks. Kerry has a reputation for being long-winded and rambling in his answers, competing messages from groups that are at least ideologically aligned with the Dems could further confuse his central messages.
(For a recent article, please see: http://www.boston.com/news/politics/advertising/articles/2004/04/12/campaign_ads_could_muddy_kerry_m
essage/)