Now available in AutoCAD 2013 is a new draw order tool. This tool will bring all leader objects to the front of the draw order.
The command for this tool is an option with the command TEXTTOFRONT <enter>
Or The draw order tool can be found on the Home tab > Modify panel Draw Order flyout and select the “Bring Leaders to Front” tool.
Below is the command line version of this tool by using the command TEXTTOFRONT <enter>
Note: that you also have the “All” option which will bring all Text, Dimensions and Leaders to the front of the draw order.