From the NYT research page on May 13:
Cardiologists at the University of California, San Francisco, reviewed 50 published studies on Taser guns, including 23 financed by the manufacturer, Taser International, or written by someone affiliated with it, and 27 conducted by independent researchers.
Twenty-two of the 23 studies linked to the manufacturer concluded stun guns were either not harmful or not likely to be harmful. Seventy percent concluded they were not harmful at all.
In contrast, just over half of the independent studies found that Tasers were either not harmful or unlikely to be harmful. Twenty-six percent concluded they were not harmful at all.
From Reason magazine's Tim Cavanaugh on May 12: Sheriffs Kill Innocent Man With Taser.