The ability to auto-create and auto-remove desktops is just fine, however this means that if you close a window and later re-open it, it will be on desktop, say, 5 instead of 2 like it was before - meaning you have to hunt for it when you want to go to the desktop with that application.

It would be much more convenient (and allow for better consistency of environment) to be able to reorder virtual desktops once created - so that if I close my browser window, and then later open it again, I can move it back to the 'second v.desktop' position again without having to reorder every other application to do so (In my case, I like my browser being the only thing on one desktop, running full screen).

Additionally, it would be nice to be able to 'pin' desktops, so that they don't auto-close when no more apps exist.  This way I could have, say, 4 pinned desktops, and they are always there, even on first login - and I can then switch to them and open the apps I normally have running in them (or choose to leave them empty if I want).  When a dynamic desktop is created, I could move it around between the pinned ones (as per above), but the pinned ones don't go away unless I unpin them and close all apps on them.  This would especially help with those of use coming from Gnome 2 world who are used to n desktops and have specific ideas of what goes on which desktop :)