Before you spend any significant amount of time trying to figure out what APIs are available for enabling drag and drop on the Spark DataGrid, I thought I’d put it out there that it will not be available in the first Hero release of the component. In flash builder, I think you will get code hints for events like dragComplete, dragStart, dragEnter, dragOver, however, you won’t find the properties dragEnabled or dropEnabled.
I believe that the team plans to add drag and drop support in the next big release after Hero, but, features haven’t been set in stone and I certainly can’t promise anything.
For now, if you really need drag and drop in a Spark DataGrid, you are left writing your own. Sorry 
I was disappointed to hear the news too.
Any update? Is drag and drop available in spark datagrid?
Looks like Alex Harui at Adobe has drag and drop working for the datagrid, but it’s not supported yet. Take a look at his code to see how you can use it.
http://blogs.adobe.com/aharui/2011/03/spark-checkbox-datagrid-with-drag-and-drop-support.html
Have you any idea about draggableColumns property ?
Also i can’t fount it