I put together the figure below to show just how erratic these Pennsylvania polls have been. Below are surveys conducted within the last week. None of these surveys has Obama breaking the 45% barrier, but Clinton's support varies from greater than 55% in the American Research Group poll to 42% in the latest Public Policy Polling survey.
UPDATE: Mark Blumenthal has posted a much better scatter plot of the recent polling in Pennsylvania along with a column on the topic. Definitely worth checking out.