There are 3 reports out recently, which are good reading from many perspectives.
University of North Carolina Charlorte – LSM Evaluation report
http://www.lmseval.uncc.edu/index.php?option=com_content&task=view&id=62&Itemid=9
U.S. Department of Education – “Evaluation of Evidence-Based Practices in Online Learningâ€
http://www.ed.gov/rschstat/eval/tech/evidence-based-practices/finalreport.pdf
Open Source Collaborative: Moodle Assessment Report
http://oscmoodlereport.wordpress.com/
I will be posting my thoughts on these later, just adding them in now, for reference!