Something that reminded me of the issues regarding Unity new ‘touch-based devices desktop paradigm’ that I noticed earlier, which I was going to mention in the previous posting: When you copy (cut/move) a large set of files, Nautilus will show you the ‘Copy File Dialog’ box. If you minimize this box, you will not be able to re-open ever therefore sort of leaving the user in the dark when the copy operation has finished. In Unity, all minimized windows go to the ‘Unity bar’ (no, NOT that kind of bar). Minimized modal dialogs that are part of applications however, do not. You cannot even re-open this box thru the ALT+TAB switch windows method. Sadly, this is a bug reported in earlier versions of Unity and it seems like it is still hanging around on (bug #887821).
In Gnome 3, they solved this slightly more elegant: Modal windows are treated the same as general system notifications and you should see it fly by in your message event ‘log’ (so to say). Switching to this dialog, however, can be achieved by using ALT-TAB and selecting the Nautilus icon. Not ideal, but definitely some Gnome developer was paying attention to properly implementing modal dialogs.
It would be interesting to see how Microsoft is solving modal dialogs in Windows 8/Metro.
Update 10/21/2012: Looks like the modal dialog issues have been fixed in Ubuntu 12.10 in an overhauled Windows switching system that actually looks pretty(see image screenshot).