Presist the state of collapsed regions/functions/etc
I was thinking it would be nice if the state of collapsed regions/functions/etc was persisted somehow so that next time you open the script it remembers the collapsed sections. This would be very useful for large scripts where you are working on a particular functionality over a number of days.
I don't see this for all scripts but maybe just for the same list that is in the most recent scripts in the File menu.
I floated this idea with my PowerShell class today and there were a number of others that expressed benefit from that feature too.
ISE persist state - would work well with remembering open files - also see (and vote if you like):
Windows PowerShell ISE: Add ability to save/load session state