From : http://blogs.technet.com/mdop/archive/2009/10/20/mdop-2009-r2-is-now-available.aspx 

Don't know what MDOP is yet.  MDOP employs six innovative technologies to increase desktop manageability, reduce TCO, and improve overall infrastructure satisfaction:

You can read one of the 44 MDOP case-studies at the Microsoft Case Study site.