Scientists are taking sides in this election. The most vocal group has been the Union of Concerned Scientists, who have taken issue with the scientific policies of the current administration, (in their assesment) its misuse of science, and (in their assesment) its hiring/appointment policies for scientific government jobs.
Embryonic stem cells and energy policy (and, tied to this, environmental policy) have been visible parts of the campaign. Other issues, such as intelectual property, other environmental issues, and space exploration have also been brought up.
Talk of the Nation has done a show with a panel, discussing the issues and where the candidates stand (two of their organizations have questioned the candidates on their positions on scientific issues).