The following code snipet

SystemWindow>>setUpdatablePanesFrom: getSelectors

	...
	getSelectors do:
		[:sel | aPane _ self paneMorphSatisfying:
				[:pane | (pane isKindOf: PluggableListMorph) and: [pane getListSelector
== sel]].
	...

It seems to me that the isKindOf: should be changed to respondsTo:
#verifyContents and would allow for a broader spectrum of things to be
updated.  I have added a new package browser that uses the hierarchical
morph and I need this feature and its not a subclass of the
PluggableListMorph.