Currently when a user clicks an icon on the desktop, Nautilus opens a new window (browser or spatial) to display the location.  This method ignores a few facts about how many people work:

1) People who have lots of windows open or limited screen real-estate (laptops) usually find additional windows a nuisance.
2) A large segment of (arguably most) people tend to work on one related set of tasks within a fairly large time interval.  

Taking these two things into consideration, it seems a more useful action when the user selects an icon on the desktop that represents a folder would be to navigate *using* the desktop.  That is, use the desktop as the window it really is. It's the largest and yet least utilized window in the interface.  Also, since there are typically single keystroke shortcuts to expose the desktop, it becomes much faster to navigate to the relevant folders and files I'm interested during a particular session.

It would probably also be desirable to have "static" icons (i.e. "Desktop", "Computer", etc) that follow the user through whatever folders they navigate and to have these be configurable.

Another "nice to have" feature would be to allow separate desktop navigation per workspace.