There's no way currently to do that in Catalyst. Drag and drop functionality would have to be added over in Flash Builder after you export your project in FC.
but you can of course "simulate" the D&D with a clever "On click, Play action sequence" interaction.
Here some information on drag and drop in Flash Builder if you want to see how drag and drop is coded:
To simply drag objects around, you can use DragManager.doDrag():
Also, there's an interesting tutorial written by Krystal Higgins, showing how she simulated a drag and drop in Catalyst, which you might find useful:
Hope this helps,
Thanks for the reply Chris. Really helps me alot.
I've manage to do couple of dragable 'Panel' using flash builder. It does not look nice, but shall do the work for now.