TypeError: 'undefined' is not a function (evaluating 'Ext.util.Observable.observe(Ext.util.Draggable)')
in Droppable.js:209

When enabled , guess its trying to observe all evenets from Draggable class but observe is something from ExtJS code base and not found its way into ST2 B3 yet...

Wish Draggable and Droppable are usable pretty soon..
Cheers