Despite these concerns, Stephan said he thinks Apple has done an all-right job in protecting its users from malicious widgets, although he did suggest that Apple rethink its logic behind the auto-install process in Dashboard and give users a way in which to remove widgets easily, preferably outside the Dashboard layer.More details at eWeek
Apple's Widgets vulnerable?

The new Dashboard widgets feature in Apple's Mac OS 10.4 has a potential security vulnerability. It seems that it is rather simple to create and install potential malicious widgets.