The following appears to have been recently added to the page: "Most recently, a new model for reflections of heat produced on the spacecraft[5] has been proposed. While this greatly reduces the amount of unexplained acceleration, it does not appear to completely eliminate it.[6]"

[5] http://www.technologyreview.com/blog/arxiv/26589/

[6] http://www.planetary.org/programs/projects/pioneer_anomaly/u...