Hi Scott,
The JInternalFrame bean is cool (and the servoymagazine article was much help when you wrote it - thanks again), and is the "windowing" part of what I am talking about, but w/o the desktop to dock these things to, they just float around like non-modals and are not much different than a regular window.
With the desktop pane you can "anchor" these windows to a parent desktop element/pane.
Regarding the MDI thread...yeah, pretty much (and swing achieves this with JDesktopPane and JInternalFrame) but more IDE "style"