Hi, 

Very interesting guesses on what constitutes dark matter: http://www.youtube.com/watch?v=lYH_nFwMXRM&feature=youtu.be 

Earlier on, a small but significant update was expected on the same topic. The findings from the experiment were not approved on time however, read more about it here: http://www.quantumdiaries.org/2013/03/05/dark-matter-retains-all-its-mystery/ 

and here: http://www.space.com/19845-dark-matter-found-nasa-experiment.html 

Martin.