The 27 March 2013 edition of the CTC Sentinel has a good update titled "Al-Shabab's Tactical and Media Strategies in the Wake of Its Battlefield Setbacks." It is written by Christopher Anzalone, a PhD candidate in the Institute of Islamic Studies at McGill University.
The article assesses the trajectory of al-Shabaab's military and political strategies, explains how defections have weakened the group, and reviews its information and media operations during the past two years following significant territorial losses.