JBoss Tools 3.0.0.CR1:
Drag and drop a component from the palette into the Visual/Source pane.
I'm working inside:
(drag h:outputText into visual/source panel here)
This works ok on Windows, but not on Linux. (I'm trying this on Fedora 10).
For Drag&Drop we are using one xulrunner listener for all OS, for OS X we haven't receive event d&d at all, on Linux receive but not all events and on Windows it works much better.